When you visit any webpage on the IP 206.63.100.249 (this privacy policy does not apply to any other IPs) it writes a line to the log which says the date and time, what host you connected from and what file you accessed. Some sites are also set up to log the referring URL, and your browser type and version.

The logs for a virtually hosted site with its own domain are only readable by the owner of that site, and are kept until the owner of that site asks that they be purged (which might be never).

Logs for http://bespin.org/~username are readable by all the bespin users, and are kept indefinitely.

Individual hosted sites may invade your privacy further (including, but not limited to giving you cookies, asking you to fill out forms that store the result or e-mail it somewhere, or executing javascript or flash code on your computer); this page is only to explain the minimum privacy invasion assuming the site owner doesn't do anything else.