[gmodena]

I really liked this overview!

For the academic inclined, there is some awesome body of work done by the Affective Computing group at Media Lab: http://affect.media.mit.edu/projects.php?id=3162

As for myself, one of the next gadgets on my buying list is the zeo personal sleep coach (AFAIK there are no affordable consumer-level competitors at the moment): http://www.myzeo.com/sleep/

Would love to hear from people with hands on experience with it.

[gwern]

> Would love to hear from people with hands on experience with it.

I suppose I could promote myself since you asked for it: http://www.gwern.net/Zeo

[coldarchon]

I would recommend the sleeptracker watch.