Here are some quotes that I've come across that I like.

"We've all heard that a million monkeys banging on a million typewriters will eventually reproduce the entire works of Shakespeare. Now, thanks to the Internet, we know this is not true."
      --Robert Wilensky

"To err is human, but to really foul things up you need a computer."
      -- Paul Ehrlich

"A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects."
      --Robert Heinlein

"Nothing in this world can take the place of persistence. Talent will not; nothing is more common than unsuccessful people with talent. Genius will not; unrewarded genius is almost a proverb. Education will not; the world is full of educated derelicts. Persistence and determination alone are omnipotent. The slogan 'press on' has solved and always will solve the problems of the human race."
      --Calvin Coolidge

"When you earnestly believe you can compensate for a lack of skill by doubling your efforts, there's no end to what you can't do."
      --Anonymous (Despair Calendar)

"You never saw a fish on the wall with its mouth shut."
      --Sally Berger, Women's Quotation Stack

"It is better to keep your mouth shut and let people think you are a fool than to open your mouth and remove all doubt."
      --Unsure - Possibly Mark Twain, Abraham Lincoln, George Eliot, Groucho Marx, Albert Einstein, Silvan Engel or a Proverb

"En boca cerrada no entran moscas."
Translation: Into a closed mouth, flies won't enter.
      --Spanish Proverb

"1. Everything that's already in the world when you're born is just normal;
2. Anything that gets invented between then and before you turn 35 is incredibly exciting and creative and, given opportunity, you can make a career out of it;
3. Anything that gets invented after you're 35 is against the natural order of things and the beginning of the end of civilization as we know it until it's been around for about ten years when it gradually turns out to be alright really."
      --Douglas Adams