Jason Kottke has posted a very amusing list of approximately 50 fun things you can do with your iPod, a kind of compendium of recent imaginative iPod uses:
42: View stereoscopic images. With two iPod Photos aligned in the proper manner, you can view stereoscopic (3-D) images just like our forbearers did in Victorian England. Save this one for the next time you have friends over for tea in the parlor.