Best of luck to it: I doubt that its guess about whether I am awake or not will be very accurate unless maps my own behavior over time. I'll bet this is true for a lot of hackers as well.

A better way would be to monitor when you are active in gmail. I bet that a pattern would emerge. If you're a nightbird your gmail activity would reveal this. If you go swimming every wednesday from 9 to 11 it would also show up. Combined with timezones and some statistics this could give a much more accurate picture, not only of when you're awake but when you're actually at your inbox.

I wish there was a device I could wear, maybe like a wristwatch, which could track whether I was awake (which is probably possible based on pulse and/or movement). It should tell my phone my status, and my phone would automatically go into silent mode while I'm asleep. It might as well display on Facebook and GChat too.

If it was accurate enough, the data on my (and everyone else's, if they chose to make it public) sleep patterns could be very interesting and even medically useful.

Something like this?

http://www.fitbit.com/

That looks great! Thanks for the link.

At first I thought you needed a device to actually tell you if you are awake or not.

Could be useful to determine whether you are dreaming. :-)

Or to make it simpler, have your phone send a note to a service whenever the alarm goes off. Usually when your alarm goes off it means you're awake :)

A Social Alarm Clock :)

You could always set your alarm clock on Twitter

http://sleep.fm/7am

Besides clicking to set it... your friends/contacts know when you will be available to respond & chat.

Timezone seems like a really poor way to do this, given all the other methods Google has for tracking their users' activity.

But this can 'track' your contacts who merely email in to your gmail account without using any other Google things at all.