Incidentally, there have been several related products in recent years. Someone (maybe Sharper Image?) was selling an alarm clock that supported downloadable alarm sounds. I don't remember exactly, but I think it worked like those digital picture frames. That's not to say that you couldn't do it better. But I think your biggest issue may be that most people don't sleep next to their computer.
I'm going to chime in and say that this doesn't seem like a very good idea. Of all the things to cram into the social trend, waking me up seems like the worst. I cannot see any reason to let my friends wake me up, or for that matter anything other than my cell phone alarm clock.
Others have suggested a FB app, but even that seems like something I would never use. Just my two cents.
Here is a full summary...
Sleep.FM - The Social Alarm Clock is an alarm clock social network, where upon the alarm time passing on the site(mobile versions soon) you are awakened by your alarm messages(audio files or voice-mail) received from your friends on the network.
It is themed around the human conditions of resting and waking where user environments are bedrooms. Users interact with one another by entering each others bedrooms to leave one another gifts(with or without comments), emails and or alarm messages.
The back button issue.. does that happen on the splash page or when you click, "Already a member? Click here," which takes you to another page?
Thanks!