I usually just take my two pinkys and pull my eyes to parallel O (don't recommend doing this though). lol
Glad you saw the Butterfly Bob; picked an easy depth map to work this time. Had a few issues with the bicycle that I used the last time I did one of these (the brontosaurus one is another easy subject). The biggest issue I have is to create a thin line seamless texture so that the resulting background texture doesn't show the line seams that you normally get. I haven't 100% mastered this yet; lucky this result worked. Forgot to mention where I got the GIMP plugin. Click the link below and scroll down til you see the Magic Eye zip file. Hard to fine compiled GIMP plugins for Windows, but this site has several cool ones that I've used over time.
http://schumaml.gmxhome.de/downloads/gimp/