At a few points in my life, teams or organizations have had whiteboards of quotes. One of my favorite and formative games, Civilization IV, had a quote read by Leonard Nimoy every time you researched a technology. Sometimes I enjoy some combination of silliness and wisdom from quotes, both in and out of context. Somewhat for fun, somewhat so you can see a bit of my personal influences, I include some quotes that I enjoy for some reason or other below. There is currently no rhyme or reason to their order, but attribution is given wherever possible.

Perfection is achieved not when there is nothing more to add, but when there is nothing left to take away.
Antoine de Saint-Exupery, Wind, Sand, and Stars
Reason, it seems, was out to lunch.
Douglas Adams, The Hitchhiker's Guide to the Galaxy
Waste no more time arguing what a good man should be. Be one.
Marcus Aurelius, Meditations
Stars, hide your fires. Let light not see my black and deep desires.
William Shakespeare, Macbeth
This is my senior quote for my high school yearbook. I was being just a wee bit edgy.
Damn the torpedoes. Full speed ahead!
Admiral David Farragut
Slow is smooth and smooth is fast.
Unknown origin, often attributed to the US Navy Seals.
I personally sometimes use the variant, "slower is faster," which is itself adapted from my dad's admonition to practice slower because then I would master a passage faster.
The best laid schemes o' Mice and Men
Gang aft agley,
Robert Burns, Ode to a Mouse
An amateur practises until he can do a thing right, a professional until he can’t do it wrong.
Percy C. Buck, Psychology for Musicians
Have you ever seen one of these grant applications? We're lucky Einstein didn't have to fill one out, or God knows what E would equal!
Martin Sheen as President "Jed" Bartlett, The West Wing
The beginning of wisdom is to call things by their proper name.
Computers are essentially fast morons. They do exactly what they are told to do, and that can be most humbling.
Bjarne Stroustrup