So I take a little vacation and when I come back, I notice this white bar along the bottom of every page on my Xanga site, and while it can be minimized a little bit (by clicking the down arrow on the right), it still leaves a small white tab sticking out of the corner "in case you want it back". Well, click on another page and the whole toolbar annoyingly comes back up again. I noticed that when I click on the "you are not signed in" part, it tries to sign me in, then fails and stupidly tells me to sign in. So finally I figured out somehow that this is a Meebo chat system, and it can be disabled.

To disable the chat bar:
* Go to Account settings and click on Chat on the left side (between Badges and Blogrings).
* On that settings page are three checkboxes for Auto Start, Public Pages, and Private Pages. Uncheck those and click on Save.

There you go - the irritating toolbar goes away! At least for your site - it seems Xanga rolled this out to everyone, so you might still get it popping up on other people's sites.