I'd come across this app pretty soon after I bought the phone, but didn't try it until just now. Gmote. I'm amazed. I highly recommend it. You use it to remotely control your computer. The main feature I installed it for was to play music from anywhere in my house, but it also has a virtual touchpad and you can move the mouse, type via our virtual keyboard, etc. Great for a home theater pc. Apparently it even works on Linux. I'm not sure how to describe it (plus I'm late for work!). Check it out, you'll love it.
http://www.gmote.org/