I just started using LogMeIn and I'm very happy with it. I have not used any others, though. I keep thinking of new ways to use it. I have been using it a lot at work to start print jobs while I am away from my desk. Actually, I am usually away from my desk, so it really is helpful. I was feeding my baby boy this morning before going to work, and I was logged into my work computer. I was able to print off the work orders for the day, which usually takes me 15 minutes or so when I get to work. This allowed me to walk in, pick up the work orders off the printer, and get and early start to my day. It also allows me to use UPS Worldship from the warehouse instead of walking all the way back to my office.
The down side of it is that I really want the wireless Apple keyboard now...