Sleepcycle.com sold for $20,000 on Sedo.
The domain registered in 2004, looks to have been purchsased by Maciek Drejak Labs AB.
There looks to be an app called sleep cycle, and they have a twitter page that has not been updated since last year.
@sleepcycle Sweden
The Sleep Cycle alarm clock is an iPhone bio-alarm clock that analyzes your sleep patterns and wakes you when you are in the lightest sleep phase.