Very nice VNC app
This is a pretty good little app, and its FREE. If you use a Mac or WinXP, you can connect to your computer from anywhere in the world. The paid version has a few extra features, but if you are an occasional user then this is the program for you.
Update: works even better with the 3Gs iPhone. With the 3G and a big screen on the iMac, I ran into memory issues once in a while.
4walls about
Mocha VNC Lite