I've already noticed that there is quite some demand for such a tool. I've got a small script that tells me how many downloads I've had for each version each day and the last output looks like this:

0.2.0: 20 (20+0)
0.2.1: 17 (17+0)
0.2.2: 154 (154+0)
0.3.0: 112 (112+0)
0.3.1: 74 (74+0)
0.3.2: 164 (164+0)
0.4.0: 164 (147+17)
0.4.1: 383 (340+43)

The first number is the total the numbers in parenthesis are jar and cod files respectively. And since I've also postet bbTracker on getjar.com another ~ 350 downloads can be added to these numbers. Of course I don't know if all those downloads where successful (probably not), but it gives a good general number.

I've got an average of about 70 visitors each day (more when I've just released a new version )

I just thought those numbers might be interesting, I personally love those kind of stats