When do they sleep?
Actors, singers, journalists, sportsmen, musicians, writers, politicians, bloggers and your friends – they are all active on Twitter now. The only time when they are not posting messages on Twitter is probably when they are sleeping.
Introducing Sleeping Time – a mashup that will help to determine the approximate sleeping cycle of any Twitter user with a click.
The algorithm uses the timestamp of the last 500 or so updates of a Twitter user to calculate his or her sleeping time. Consider this app in the early pre-alpha stages so please let me know if you encounter any bugs or if your sleeping report is way off the actual pattern.