Alright, I know this is wicked old, but since mikegayle already bumped it...
If you have the chinga to toss around, try LogMeIn ignition from the app store. It's like $30 but you can easily log into your PC or Mac from your iPhone/iPad/iPod touch and it works really well with pretty good screen res. Though there may be other, cheaper VNC options out there that should work well too.