The following comes from Wiz, a fellow tech guru friend of mine, in his words:
LogMeIn Ignition is a LogMeIn client for the iPhone.
There’s a video demo here: https://secure.logmein.com/welcome/iphone/
This app remote controls any PC or MAC that has the LogMeIn software installed on it, and yes – you can have the free version of LogMeIn on your PC/MAC – the only license fee to pay is for the LogMeIn application on the iPhone.
It works very well even across 3G. I’ve used it toremote into my home PC on a few occasions for urgent emails etc.
The one thing which makes this remote access app significantly better that the others is a single important concept. You’d probably imagine that using a remote desktop app on a mobile device of any kind can be hard to use. Even harder when you are trying to use your fingers to click onthings.
LogMeIn gets around this problem by keeping the mouse stationary while you scroll the screen around. This way you can “click”anywhere on the screen. It’s very precise and accurate. It might sound a little funny, but it’s surprisingly effective.
If you want to spend serious money, they also have remote access apps for “customer on demand” style stuff so you can remotely connect to a customer’s PC without anything being previously set up. While that’s pretty awesome in itself, for the money they charge you could more easily use something like the UltraVNC “SingleClick” application to achieve almost the same thing.