Okay, so you thought if you want to be invisible you’ll always have to sign into Gmail? I’ll give you a solution. Bookmark this link in firefox,
http://talkgadget.google.com/talkgadget/popout
Right click this bookmark, click on properties. Then check ‘Load this bookmark in the Sidebar’.
Go ahead, and log in. Now you CAN be invisible without having to loging in to your gmail account always.
Stumble it!