Not really sure Discussions does this.

You might tinker around with the member profiles stuff built into the core and see if that gets you closer to what you want.

Ok thanks I'll take another look at that. I was hoping that I could use it for a Signature when a user makes a post, or preferably to display it alongside their other info on the left of their post.

Many thanks,
Mike

I'm afraid there isn't a signature feature built in.