I've been a long time user of logmein , and have been interested in the iPhone app, but it has always been a little expensive ($36.99) so I never got around to purchasing it.
Now TeamViewer's iPhone app is free for non-commercial use. Before today I've never heard of them, but I've installed it on a few computers - a small <10MB app that sits in system tray - and you can access from any web browser, or the app, or on your iPhone. It works surprisingly well on an iPhone 3GS over 3G.
It's great for putting on friend's and relative's computers so that whenever they have a problem you can fix it without leaving your home (or getting off the toilet if you have an iPhone
). Of course having access to everyone's computers might only increase the amount of support requests that you'll get!
[/url]