Yep, gotta be a link to somewhere. As far as, if you happened to mean displaying level and such in your sig, people just manually edit them to reflect current levels, etc.
Warlord,
One sig I made that used to work on ezBoards and phpBB used javascript loaded from a file on my server to make the sig dragable. You could click and drag the sig around the screen. It also kinda proved to the people that maintain that software that there were ways around some of the anti-script protection they had in place. =)