BoingBoing's Mark Frauenfelder did an interview with Jesse Thorn on the podcast Bullseye. He describes the Zeo sleep manager, which gives you a read-out on your past night's sleep (I need one!).
And he also recommends GurneyJourney (around the 4:00 mark).
Direct link to interview
Thanks, Mark -- and Heather for telling me about it.