throw out the baby with the bath water — to lose the good parts when you get rid of the bad parts of something [freedict]

This is a useful phrase to use in a debate or argument. On the second day of the workshop, there was a panel discussion on the topic of “Electronic Voting”. Experts in the field were gathered to scrutinize this problem from different angles. One of them threw out a radical opinion: E-voting is useless and it’s completely a waste of time and money. He then substantiated his view by enumerating problems existent in all the proposed voting protocols. A cryptographer didn’t agree with him and said: “You cannot throw out the baby with the bath water.”

shoot oneself in the foot — Foolishly harm one’s own cause [dict]

On the first day of the Workshop on Privacy Enhancing Technologies, an invited speaker delivered a keynote speech on the moral and ethic values a scientist should possess. In particular, she praised the efforts by “Pugwash” — a conference that promotes ethics among scientists. However, one attendee did not quite agree with the speaker. He started his question with: “I am probably shooting myself in the foot here by saying pugwash is not good. …”

don’t poke the bear — to do something provocative or dangerous [UsingEnglish] [phrases.org.uk]

I heard this phrase from a movie. An alternative expression, more commonly used but less vivid, is: “let sleeping dogs lie“.

someone sits there like a lemon — to describe a person in a socially awkward situation [see lemon]

In a movie, Monk is a highly gifted detective. He, however, is awkward to deal with people. Once, he becomes very nervous when sitting next to a stranger. Seeing this scene, someone says, "Look, he sits there like a lemon". There are some discussions about why the word "lemon" in this phrase. One explains this way: a lemon is "small enough to miss in packing and round enough to roll out of sight". I don't know whether that truely explains the origin of this phrase (maybe not), but it certainly shows a mnemonic way to remember.

pull down — to draw money as wages [dict]

On a movie, a cop's girlfriend is a lawyer and makes good money. She wants the cop to quit his job and says: "I pull down enough for both of us".

trip up — Make or cause someone to make a mistake [dict]

On 'The closer', Brenda, the deputy police chief in LAPD, has a gifted ability to make suspects talk. Before an interrogation, she said to others: "I will give him a little pressure. And he will trip up."

run out of steam — to lose the energy or interest to continue [freedict]

At yesterday's seminar was an invited talk on the mobile phone security. The speaker was busy answering questions from the audience during the Q&A session. When I started worrying that the session would never end and we would have to miss the approaching England vs Sweden wold-cup match, the audience suddenly fell into silence. "Since we have run out of steam," the host spoke conclusively, "let's thank the speaker."

push one's luck — Risk one's good fortune, often by acting overconfidently [answers.com]

If you read my previous blog, you may agree with me on how hard it is to get a computer upgrade in our department. Recently, a guy requested a better computer on the research grounds. He was lucky enough to be assigned with a relatively new machine, with a fast CPU and a big memory. Not yet satisfied with the monitor, he raised another request for a good LCD monitor. One of the staff in charge of this wasn't very happy and said to me: "He is pushing his luck."

square up — settle conclusively; come to terms [dict]

Last weekend, the world-cup match between America and Italy turned out to be such a drama: one goal from Italy at start, quickly followed by an equalizer from America. But that was only the prelude. One Italian player was later sent off the pitch for a red-card. When everyone thought that the game was now tipped to America's advantage, two Americans were subsequently expelled for red-cards. However, in the remaining time, Italy failed to convert the advantage of having one more player into any goals. The game ended up with a 1:1 draw. At one scene during the game, two players from both sides clashed, attempting to gain the ball. The Italian player got up and "gently" massaged the American player's head, while the American "gently" patted the opponent's back. The TV commentator said: "That is relatively friendly squaring up."

on ice — Assured of attainment or success [dict]

On 'The Closer', Detective Hubbard killed his former partner for personal revenge and fabricated the crime scene to frame another Detective, Xavier. Brenda sensed something suspicious with Hubbard. Pretending that she needed help, Brenda asked Hubbard to be involved in interrogating Xavier. Without knowing this was a trick, Hubbard readily agreed. "You must catch that guy," he said to Brenda firmly, "I mean on ice."

bump up — increase, raise [dict]

At a party, referring to a pay rise, someone said: "They will bump up my pay next year."

sought after — Very popular, in demand [dict]

Someone was eager to watch the football match between Brazil and Croatia. He said, "This match is sought after." 

shore up — support [dict]

Yesterday on ITV news, some members in our research group demonstrated the cracking of the "Chip And Pin" cards issued by banks in the UK. Using the cloned card, the reporter was able to draw money from the ATM machine (from his own account). With a shivering voice, the bank spokeswoman still tried to assure the audience that the cards were safe. "Banks are fighting to shore up public confidence," the reporter commented at the end of the interview.

put words into someone's mouth — to tell someone what you think they mean or want to say [thefreedict]

I have a football buddy and we have played together for many years. To justify blowing half a day's time on the football pitch, we also share the same cover story to tell our wives: "He is already waiting for me on the pitch and it would be so rude to stand him up." This had worked well until yesterday when we were invited to their house and the wives found out the correlation between the lines. This buddy happens to be able to cook delicious foods. I praised him: "I wish I could cook as well as you." My wife quickly "clarifies" for me: "He means he won't play football with you any more until he cooks as well as you." "She puts words into your mouth," the buddy's wife laughed and said to me.

ring a bell — To arouse an often indistinct memory [dict]

I asked someone a question: "Have you heard of this name?" "It rings a bell," he replied, "But I don't know much about the details."

mooch off of someone — expect someone to pay your expenses [dict]

On 'Friends', Joey and Ross were mistaken to think that Chandler shunned them because he was mad about their not buying him a Knicks game ticket. "We are supposed to buy him a ticket?" Joey said to Ross, "That guy is always mooching off of us." It seems, according to dictionary.com, that "mooch off someone" without "of" is also correct.

no jib jab — stop talking trash [urban]

On 'Lost', Jack, Sawyer, Kate, Hugo and Michael were fully armed and set out to look for the "others" — mysterious people living on the other side of the island. Michael tried to convince his teammates that the "others" were just a bunch of hillbillies, nothing to be afraid of. Kate, however, was sceptical about that. Recalling the consumes and fake beards she had found left by the "others", Kate cautioned that the "others" might simply trick them into believing that they were hillbillies. Unhappy about these speculations, Sawyer said: "Alright, no jib jab. Let's go."

chop chop — Right away; quickly [dict]

Last Saturday afternoon, I played football with some friends in Parker's Piece meadow. It was an informal game, with fresh players joining in from time to time. After playing for 2 hours, we felt exhausted and decided to take a break. However, a few late comers, with yet spare energy, were keen to get everyone back to the field and continue the game. "Come on," one of them urged, "Let's play. Chop chop." 

backhanded compliment — an insult disguised as a compliment [wiki]

When I read an article on 'The Times', I came across this phrase — "backhanded compliment". The article is about an interview with the former football star: Pele. He is invited to comment on the 2006 Brazil world-cup squad and compare with the 1970 side at his peak time. He praises that this year's team is great, but if two teams were to compete, his 1970 team would win. In the article, his comment is described as "a backhanded compliment". Well known in the world, Pele is such a hilarious talker. I remember a few days ago he predicted that Brazil would win out in the forthcoming world cup. But his "patriotic" speech incurred vehement protest back at home in Brazil, because he always predicted wrongly.

goose bumps — momentary roughness of the skin from cold, fear, or a sudden feeling of excitement [dict]

On 'Friends', Chandler was going to propose to Monica. He asked Phoebe to help him pick out a ring in a jewelry store. Interested in a nice princess-cut diamond ring, Chandler asked the jeweler to hold the ring and pretend to propose to him. Feeling the excitement from this rehearsal as if Monica would feel the same, Chandler decided to buy this ring. He asked Phoebe to stay and guard the ring, meanwhile he went back home to get the forgotten credit card. However, the playful Phoebe didn't fulfill her duty and the ring was bought by someone else. Guilty about this, Phoebe tried to persuade Chandler to pick a different ring, but Chandler didn't buy. "When he proposed to me with the ring," he explained, "I got goose bumps." "Maybe it was the guy," Phoebe quickly interpretted. "No. It's the ring," Chandler said firmly.