I remember, back from my Trillian using windows days, that when i was configuring a new account (say AIM), i would have a button that would let me create an AIM account if I happened not to have one (i.e., linked me to AIM's registration website), Trillian may not have had this feature (it's been a long time...), but it would be useful nonetheless, and remarkably easy to code (all you need to to do is find the registration page URLs for every client, and make a button linking to them in the respective account windows...).
yelly