Windows SideShow for Mobile (Developers Beta)
This was a cool little drop that seems to have flown under the radar. If you have a Vista laptop (and if you don’t then there’s something wrong) and a Windows Mobile Smartphone (see last comment) and they are paired via BlueTooth then this is for you. The install is Sideshow for mobile and after you install the Office PowerPoint gadget you can control your PPT from your phone as well as see your speaker notes on the phone.
Windows SideShow for Windows Mobile Developer Preview
Installation is pretty straight forward, just follow the installation doc and you should be good to go.