Yes, browsing this forums - obviously. But what else?
I just installed another Linux OS without any need.
Stupid, I know. Wasted precious hours configuring soundcards (on-board, hdmi-audio, regular soundcard), dvb-t tv-settings, etc etc... and managed to surf giantbomb.com with a text-browser from a console, the ominous w3m:
on the left you see the regular Firefox 3.5.5 and on the right there is the Giantbomb Off-Topic Forum looking pretty dark. Although I could not login. Damn you, Javascript!
All the minor and major-league Websites get to see who visited their Website from what IP address, with what Webbrowser, on what Operating System (unless you choose to hide some of this information).
So if you have your Amiga or Commodores around connected to the interwebs, pay the site a visit and make Dave cringe or put a smile on his face. They see the stats in their log-files/Web-Analytics.