hi,
Check out Snooggie which is a free and anonymous instant messaging site for communities. The site is an instant messaging software like messenger but unlike them it is not based on a personal contact list. You register get a URL and who ever enters the URL is added to the currently online list. You can then chat with anyone on the list.
A way to implement Snooggie is to create a community, get the URL and post it on your site as link, people surfing your site can then chat with each other or only with the community owner
