I did exactly that after looking at this thread, and only spotted your comment when I wanted to post the results.

I skipped some obvious refinements as this was a 5 minute project.

• 55 A Bet is a Tax on Bullshit. Alex Tabarrok
• 45 Luck is statistics taken personally. Penn Jellete
• 33 Comic Quote Minus 37 -- Ryan Armand Also a favourite.
• 34 Nobody is smart enough to be wrong all the time.Ken Wilber
• 32 A problem well stated is a problem half solved.Charles Kettering
• 48 I will not procrastinate regarding any ritual granting immortality. --Evil Overlord List #230
• 29 The greatest weariness comes from work not done.-Eric Hoffer
• 26 "Most haystacks do not even have a needle." -- Lorenzo
• 24 "I accidentally changed my mind." my four-year-old
• 31 Doubt is not a pleasant condition, but certainty is absurd. Voltaire
• 39 People say "think outside the box," as if the box wasn't a fucking great idea.Sean Thomason
• 38 The Noah principle: predicting rain doesn’t count, building arks does. -Warren E. Buffett
• 37 It’s easy to lie with statistics, but it’s easier to lie without them. -Fred Mosteller
• 30 If one does not know to which port one is sailing, no wind is favorable.-Seneca
• 34 It is the mark of a truly intelligent person to be moved by statistics.George Bernard Shaw
• 34 "Working in mysterious ways" is the greatest euphemism for failure ever devised.TheTweetOfGod
• 12 Death is the gods' crime. Unsounded
• 24 The most practical thing in the world is a good theory. Helmholtz
• 29 When the facts change, I change my mind. What do you do, sir? John Maynard Keynes
• 28 Writing program code is a good way of debugging your thinking. -- Bill Venables
• 28 It is easy to be certain....One has only to be sufficiently vague.Charles S. Peirce
• 30 Truth is much too complicated to allow anything but approximations. — John Von Neumann
• 31 There is one rule that's very simple, but not easy: observe reality and adjust. Ran Prieur
• 21 Things are only impossible until they're not. -- Jean-Luc Picard
• 24 Part of the potential of things is how they break. Vi Hart, How To Snakes
• 25 A scholar is just a library’s way of making another library. Daniel Dennett
• 29 We should be careful to get out of an experience only the wisdom that is in it. Mark Twain
• 29 The Company that needs a new machine tool is already paying for it. -old Warner Swasey ad
• 25 "Any sufficiently analyzed magic is indistinguishable from SCIENCE!" ~Girl Genius
• 26 Complex problems have simple, easy to understand wrong answers. — Grossman's Law
• 22 Most people would rather die than think; many do. – Bertrand Russell
• 22 The only road to doing good shows, is doing bad shows.Louis C.K., on Reddit
• 28 My brain technically-not-a-lies to me far more than it actually lies to me.-- Aristosophy (again)
• 23 The truth will set you free. But first, it will piss you off. Gloria Steinem
• 27 Nature draws no line between living and nonliving. -- K. Eric Drexler, Engines of Creation
• 22 It is better to destroy one's own errors than those of others. Democritus
• 12 Reality is not optional. Thomas Sowell
• 17 Statistics is applied philosophy of science. A. P. Dawid
• 22 Forget Jesus. The stars died so that you could be here today. Lawrence Krauss
• 23 Go down deep enough into anything and you will find mathematics. Dean Schlicter
• 24 We are built to be effective animals, not happy ones. -Robert Wright, The Moral Animal
• 19 Being right too soon is socially unacceptable. Robert A. Heinlein
• 14 "Anything you can do, I can do meta" -Rudolf Carnap
• 17 Mind is a machine for jumping to conclusions - Daniel Kahneman
• 26 A faith which cannot survive collision with the truth is not worth many regrets.Arthur C. Clarke
• 26 Nobody panics when things go "according to plan"… even if the plan is horrifying. The Joker
• 23 "Convictions are more dangerous enemies of truth than lies." --Friedrich Nietzsche
• 20 I honestly don't know. Let's see what happens. -- Hans. The Troll Hunter
• 16 Luck is opportunity plus preparation plus luck.--Jane Espenson
• 20 The singularity is my retirement plan. -- tocomment, in a Hacker News post
• 19 Better our hypotheses die for our errors than ourselves. -- Karl Popper
• 22 Errors using inadequate data are much less than those using no data at all.-Charles Babbage
• 19 In general, we are least aware of what our minds do best. — Marvin Minsky
• 20 It is easier to love humanity than to love one's neighbor.--Eric Hoffer, on Near/Far
• 15 Keep your solutions close, and your problems closer.afoolswisdom
• 18 "If God gives you lemons, you find a new God."-- Powerthirst 2: Re-Domination
• 17 Truth comes out of error more easily than out of confusion.-Francis Bacon
• 23 Opening your eyes doesn't make a bad picture worse. http://onefte.com/2011/07/17/bully-for-you/
• 19 Know the hair you have to get the hair you want. -Pantene Pro-V hair care bottle
• 16 The best way to escape from a problem is to solve it. -Alan Saporta
• 16 Not to know is bad; not to wish to know is worse. — Wolof proverb
• 20 Those who can make you believe absurdities can make you commit atrocities. -- Voltaire

If we're looking for a short, pithy statement which signals affiliation with the Less Wrong meme cluster, I think the standing all-time top rationality quote is a good place to start.

Personally, I've been hearing all my life about the Serious Philosophical Issues posed by life extension, and my attitude has always been that I'm willing to grapple with those issues for as many centuries as it takes.

-- Patrick Nielsen Hayden