I'd vote for Asterisk + fax server as the next sample project, I would think those should go together nicely. I've been planning to build one of those myself, to leverage all the multi-function jacks I installed around the house.
In one of the usenix ;login: issues they integrated asterix with mythtv, so you can even tie this back in with the original project. (Stuff like putting caller id on screen instead of ringing the phone when watching a movie).
Clifton Royston -- [EMAIL PROTECTED] / [EMAIL PROTECTED]
Tim Newsham http://www.lava.net/~newsham/