For controlling your computers - check out Air Mouse
It seems to work on any PC or mac system...from your iPhone. (Ya just gotta love the 85,000 strong app store) This one is only $1.99 for now.
I just bought the air mouse app and I can control my mac from anywhere within the wi-fi range of my router.
I was in the other room making music selection changes in iTunes back on the mac. Its like a wireless/portable touchpad and keyboard. I will be experimenting with it over the next few days and report back.