I saw this on the medwebmasters list*:

If I have seen further it is by standing on the shoulders of giants.
- Isaac Newton (1642-1727), Letter to Robert Hooke, 5 February 1676, in H. W. Turnbull (ed.) Correspondence of Isaac Newton, vol. 1 (1959)
p. 416

If I have not seen as far as others, it is because giants were standing on my shoulders.
- Hal Abelson

A dwarf standing on the shoulders of a giant can see farther than the giant himself.
- Stekel

A dwarf on a giant’s shoulders sees farther of the two.
- George Herbert (1593-1633), Jacula Prudentum (1651)

A dwarf standing on the shoulders of a giant may see farther than a giant himself.
- Robert Burton (1577-1640), The Anatomy of Melancholy (1621-1651), “Democritus to the Reader'’

If we stand tall it is because we stand on the shoulders of many ancestors.
- Yoruba Proverb

In the sciences, we are now uniquely privileged to sit side by side with the giants on whose shoulders we stand.
- Gerald Holton

Bernard of Chartres used to say that we are like dwarfs on the shoulders of giants, so that we can see more than they, and things at a greater distance, not by virtue of any sharpness on sight on our part, or any physical distinction, but because we are carried high and raised up by their giant size.
- Bernard of Chartres (d. c.1130), John of Salisbury Metalogicon
(1159) bk. 3, ch. 4

In computer science, we stand on each other’s feet.
- Brian K. Reid

It is a special trick of low cunning to squeeze out knowledge from a modest man, who is eminent in any science, and then to use it as legally acquired, and pass the source in total silence.
- Horace Walpole

Stealing from one source is plagiarism. Stealing from many sources is research.
- Laurendo Almeida

Copy from one, it’s plagiarism; copy from two, it’s research.
- Wilson Mizner (1876-1933)

Rules of Creative Research:
1) Never draw what you can copy.
2) Never copy what you can trace.
3) Never trace what you can cut out and paste down.

Everything important has been said before by somebody who did not discover it.
- Alfred North Whitehead

When we ask advice, we are usually looking for an accomplice.
- Joseph-Louis LaGrange,

Our best thoughts come from others.
- Ralph Waldo Emerson

We all have the capability for a good idea. We should have the ability to protect them, and the wisdom to share them.
- Jack Kirby

I may be given credit for having blazed the trail but when I look at the subsequent developments I feel the credit is due to others rather than to myself.
- Alexander Graham Bell

The most exciting phrase to hear in science, the one that heralds the most discoveries, is not “Eureka!” (I found it!) but “That’s funny…”
- Isaac Asimov

*Stephen Pribut’s sig.