Squirrel Thieves!!

So how do ya keep squirrels from raiding the bird feeder... and without shooting them to all to hell with the shotgun? : ) Any suggestions? I catch these little buggers everytime... I snuck up on this little goober and when my digital camera made a tiny "beep" noise, he looked right at me! Gotcha! Is that a guilty look or what? I am gonna bring some extra seeds and put 'em on the ground, hopefully so these guys won't steal all the bird seeds.