If you want to join, email me at email@example.com. Put "The Silence Project" in the subject line of your email. You'll have to have a blogger.com account.
The rules are simple: record less than 20 seconds of what you think is silence, post it to whatever file service you choose (I suggest the Internet Archive), and sit back and enjoy the silence.
In any case, here is my first prototype for The Silence Project: