FIREMIN  When I had a Nokia phone I used Salling's Clicker to make the phone a remote. Air Mouse is a great replacement now I've gone iPhone. In both Trackpad and Air modes it works well. I'm still fiddling with the sensitivity, but am happy with it so far. The four customisable key stroke combo's are very handy! Very useful app if you want to, for example, control a Keynote / Powerpoint presentation without having to stand at your computer!  
(Version 1.5.5)

LLONGLEY  This is one of the coolest apps I have seen so far for the iphone / mac combo. It works flawlessly with my entertainment system connected to a mac mini. Once you get the iphone app you download the server for your mac and away you go. The really cool thing is that one of the problems with using a mac for a media center is controlling the mac with out keyboards and mouses all over the family room. This mouse has the keyboard built in and it works great "in the air" no table or flat surface needed. Great App!!!  
(Version 1.5.5)

RYANSEBIZ  Must-have app for any HTPC (Mac or PC).

This transforms your iPhone or iPod touch into a virtual mouse and keyboard, allowing you to ditch the other hardware laying around your couch.

Fantastic app.  
(Version 1.5.3)