Alas, I was bored today:

[*IMG]http://i2.photobucket.com/albums/y31/bandchick182/archimedes_userbar.jpg[/IMG*]

[*IMG]http://i2.photobucket.com/albums/y31/bandchick182/curie_userbar.jpg[/IMG*]

[*IMG]http://i2.photobucket.com/albums/y31/bandchick182/galileo_userbar.jpg[/IMG*]

[*IMG]http://i2.photobucket.com/albums/y31/bandchick182/newton_userbar.jpg[/IMG*]
And last but not least...

[*IMG]http://i2.photobucket.com/albums/y31/bandchick182/einstein_userbar.jpg[/IMG*]
I tried to come up with a creative one for Da Vinci, but I couldn't find a good equation to put in there.
If you were wondering the equations are:
Archimedes: π = 3.14... and the image is a pie
Curie: Ci =
226Ra and the image is the radiation symbol
Galileo: D= t
2 and the image is a falling rock
Newton: F = ma and the image is an apple (ok, I was lazy with this one)
Einstein: E=mc
2 and the image is an hour glass (yeah, lazy here too...)
Like Travis, remember to take the stars out if you put them in your signature!