Actually, there is a small referrer system built in, however I truly hate the reports and am working on some ideas to make it a little more useful.

Good idea on the features list, I'll put something together.  Also I hope to have the demo up and running sometime soon.  I now find myself refusing to give dates anymore, as every deadline I've set for myself has slipped lately because of work.

Just add a Email-to-a-Friend script to it. Then you can just add the link where needed and you will kill 2 birds with 1 stone. You can add this link in the emails that go out too.
When you click the link, you get a page that has several, the number would be up to you in the admin maybe, input text boxes for thier name and email address. Of course you want a disclaimer on this page that the email addy of your friends will not saved or marketed. It will only be used this one time.
Just a cover your rear statement!
So this way you can now send the info, page, etc...to 1 or as many friends as you want.