Note: This app is only for jailbroken iPhones.
The TiVo Remote app has been around for quite a bit now, but it was recently updated and actually became worth downloading.
The iPhone wirelessly sync to your TiVo (which must be series 3) and allows you to control it via the UI displayed above. It literally turns your iPhone into a remote control.
Furthermore, the iPhone downloads the data about the shows you have on your "Now Playing" list so you can read, review, and select shows right from your iPhones screen (in case you prefer your precious 3.5 inch screen over your 55 inch plasma).
The app can also use the NPL data to start playing the recordings automatically.
Download it from Installer.app and add the following source: