Who doesn’t loves statistics? Ever wanted to know how many users use GNU/LINUX? How many use a particular distro? Below are two sites which keep a track of Linux users. One can get his machine registered to get into the official Linux universe. Furthermore you can even use the badge to showcase in forum signature or on your website.

Linux Counter

Ubuntu Counter

If you know counters for other linux distros, mention them in comments so that I can merge them in the main post.