I understand why you want to allow HTML, but it can be used maliciously to attack your site, just so you know...but right now vshare 2.6 only allows html through the admin area (which is a much more secure way of doing it IMHO).

Perhaps (for now) you can put a post somewhere on the site that if a person wants their site linked, they can submit it to you and you can add it? LIke one of those "submit your site" form kind of things IDK....maybe something like this found here http://www.ascadnetworks.com/cgi/lm.php or here http://www.scriptarchive.com/links.html