There’s a guy (lordv) on Flickr with an absolutely fantastic set of macro (very close-up) photos from nature, featuring lots of flowers and insects. On top of that, he has a recent set wherein two images are shown, and if you do the cross-eyed 3D thing, you get a 3D macro image.  It’s fantastic. The photo set is here. 

Here’s the one with the best depth I’ve seen so far:

It helps if, after you get the 3D image locked in your brain, you use your hands so that you can’t see the ‘extra’ images on either side. Then you can examine the picture without losing the lock as easily.
ADDENDUM 2005-12-23 @ 21:56: Look, I did it with our heart model!

Technorati Tags: macro, photography, flower, 3D, cross-eyed, Flickr