(I've gathered these during my many years of travel around the Internet. I've used many; claim authorship of none. I'll add to this list periodically.)
"Been there. Done that. Reincarnated."
"What's all this about hellfire and Dalmatians?"
"Veni, vidi, Velcro: I came, I saw, I stuck around."
"Got a 486 for my wife -- good trade."
"The four food groups: Fast, Frozen, Instant and Chocolate."
"What this country needs is a good 5-cent quarter."
"Neutrinos have mass? I didn't even know they're Catholic!"
"I wouldn't be caught dead with a necrophiliac."
"I know it all, I just can't remember most of it."
"If reality wants to get in touch, it knows where I am."
"Learn from your parents' mistakes - use birth control!"
"Hard work has a future payoff. Laziness pays off now."
"Friends help you move. Real friends help you move bodies."
"System error - press F13 to continue."
"No, I'm not an elitist. Why do you ask, peasant?"
"Did you expect mere proof to sway my opinion?"
"Smokey the Bear says, "Strip mining prevents forest fires."
"Quoth the Raven, 'Eat my shorts!"'
"The most affectionate creature is the wet dog."
"I was born alive. Isn't that punishment enough?"
"Computing is a terminal condition."
"My superiority complex is better than yours!"
"`Hey, can I get something to drink?' -- Socrates"
"`I drank what?' -- Socrates"
"Everything's falling into place - on top of me."
"I won't rise to the occasion, but I'll slide over to it."
"Boldly going forward because we can't find reverse."
"Karaoke is the Japanese word for `tone deaf.'"
"What is a `free gift?' Aren't all gifts free?"
"A manager does the thing right. A leader does the right thing.
"The secret of teaching is to appear to have known all your life what you
learned this afternoon.
"What do you do when you discover an endangered animal that eats only
endangered plants?
"Being in debt is one way of proving that is possible to have less than
nothing."
"Do witches run spell checkers? "
"My brother sent me a postcard the other day with this big satellite photo of
the entire earth on it. On the back it said: 'Wish you were here.'"
"One business author recently estimated the average American encounters
something like 2,000 sales messages a day."
"Confidence is the feeling you get just before you fully understand the
problem. "
"My girlfriend does her nails with white-out. When she's asleep, I go over
there and write misspelled words on them."
"The Concorde was great. It travels at twice the speed of sound. Which is
fun except you can't hear the movie till two hours after you land. "
"Progress doesn't enlighten people -- it just makes them stupid in new ways."
"My father built a quicksand box in our back yard. I was an only child,
eventually."
"One of the worst of my many faults is that I'm too critical of myself. "
"If a parsley farmer is sued, can they garnish his wages?"
"Do you think that when they asked George Washington for ID that he just
whipped out a quarter?"
"One thing the inventors can't seem to get the bugs out of is fresh paint. "
"My friend Winnie is a procrastinator. He didn't get his birthmark until he
was eight years old."