Your spaces page has a little section called "updated spaces." When someone updates his or her page, that section of your page changes randomly. At one point, this page was the one that was randomly listed in the "updated spaces" section on your page. Then, someone looking at your page [one of your friends, maybe?] clicked on the link to this page. In the "settings" section for your Spaces page, you can see where the people looking at your site clicked to get to your site, and someone who looked at this site came here from clicking on a link in your page [in the "updated spaces" section].

I thought it was a funny thing to have happened, but oh well. If you don't want to link to people you don't know, go to "customize" then get rid of the "Updated Spaces" module.

My page showed up as "sequelitis"