Oh, that's how you do Whooiz with Community Server...
When I first put the link to the bit of script to list my Whooiz Friendz, it didn't work. It would just display as the link. Seems <script would be replaced with <script - but there's an answer!
http://communityserver.org/forums/thread/496622.aspx shows you how to tell Community Server to allow things like this. A quick tweak to communityserver.config (or in my case, a quick email to the ever-helpful Susan Bradley), and hey presto!
So now my friendz are listed nicely. :)