I just saw this while I was signing out of an account

http://rohit11.com/share/outer-court/gmail-signout.png

is this something new?
Seems like, cause it gave false alert on a very legitimate signout :)

I'm not sure, but I guess this is available probably since the "last account activty" feature was rolled out.

(more information about the "last account activity" thing in http://mail.google.com/support/bin/answer.py?ctx=gmail&answer=45938)