If you're willing to put a little more time and effort into it, you can have a computer working like a Tivo, only better. There is an application for linux called MythTV that has a tv tuner, tv recorder function that records at full quality and automatically transcodes to whatever format you like (ie. XViD), download tv schedules, schedule recordings like Tivo, rip and burn DVDs, rip and burn audio CDs, and manage your recorded library.

There's a modified Knoppix distribution called KnoppMyth that makes the installation almost brainless -- no interaction with the console if you don't want to. KnoppMyth is free and will work on even an old, slow PC. It also supports many different tv tuner cards including old ass WinTV cards based on the BT484 (Brooktree) chipset. These badboys are cheap on ebay or half.com.

If you already run linux, there are gentoo, debian, and redhat packages for MythTV as well as some of the alternatives including freevo.