[sclitheroe]

I cannot say enough good things about LogMeIn, which is free for personal use as well. I recently used LogMeIn to fix a Mac and a PC in Dubai. Works very well. I also had an engineer here in Calgary run SolidWorks CAD on a multi-monitor workstation remotely from a Macbook while on vacation, and it was able to handle that beast of a graphics app too with no issues.

Edit: I didn't see that you don't want something that runs in the background all the time - LogMeIn will run as a service by default. Honestly though, its quite lightweight, and very stable. I wouldn't worry about that too much, and once you fix something remotely once, you know you will be called upon again in the future....