I thought I would offer up a resource I use to gather user data (a web developer/designer's must have). I know there are several user stats gathering sites online, but this one seems to gather actual user data.

Check out http://www.thecounter.com/stats/

The Counter is a place where you can add a page counter to your site, and this counter gathers user information other than just how many times your page has been "hit". The global info is data from all their subscribers, it gives information on what browsers are being used, what OS, resolution, color depth, and more, and breaks it down into averages for each.

It's worth a look!