Yuku free message boards

Is there a way to show (in the post author block under IP address and such) the length of time someone has been a member of your community? There's been some things going on lately on my board and I think this would be a valuable add-on (for my moderators and others) due to the fact that I've taken a couple of forums invisible with restrictions on length of membership for visibility.

I've gone through the script library and there isn't anything there, so I was wondering if there's something else out there?

Thanks in advance...
-Ann-