I think that there needs to be some sort of url validation on the links to other social sites in the profile.  It needs to vaildate first of all that it's a valid URL.  Ideally, it would also validate that the link is going to facebook, twitter, myspace, etc..  Wouldn't want people putting other links in there.

The first time that I set it up on my profile, I just assumed that I needed to put in my email address or account name and the link would be automatically generated.  I was mistaken.  What's really needed here is the full link to your profile on facebook or twitter or whatever..  So what happens is, a broken link to a non-existant page in your site.