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.m

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 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/ http://www.myzeo.com/sleep/ Would love to hear from people with hands on experience with it.