I've been an AR member for about 6 weeks now.
When I first joined, I'm guessing that there were approximately 14,000 members. Occasionally there may have been 350 or so online at the same time.
The numbers have swelled since then, and we are gaining some serious momentum. It wasn't that long ago where I read a post congratulating member #20,000 joining AR. That might have been about a week ago.
As I post this, the readout states that there are 21,750 members and that there are 1,002 online now. This is at 7:50 pm EDT 3/21/2007.
That is a phenomenal rate of growth, and a very high percentage of users online at the same time.
Congratulations to all of us!