Now here's a mod that would be of great use to me. I run a board where several members have multiple characters -- and every time they want to switch, they have to log out and log in as the other membername.
It would be extremely handy if they could just switch "Profiles" -- say by choosing a profile from a drop-down box in the header, for instance. Many may not like the idea because it would allow people to be not only anonymous, but have multiple personalities. But for a board like mine, it would be invaluable. Besides, its easy enough to find out the membername behind a profile name.
Sadly, I don't have time to develop this mod -- all of my PHP development time goes into my CMS, and I really only get to that about one hour per month these days.

I just think that if someone was looking for a really cool, original project, this might be worth looking into.