Hello!
I've been working on my first plugin for a while, and I don't even know if it's useful! It deals with users with websites to promote for fun or for profit. The concept is this: users can specify tags in their profiles possibly related to their website. Then, in the topics they start, everytime another user use one of those words in their posts inside the topic, these words are wrapped in a link to the topic poster's website.
Am I clear? Now you too can have annoying intellitxt's on your forums =) without the thousands of visitors! And you're not referring to big advertising companies but to your dudes with a web presence. It is a give and take thing. Cause you might raise their pagerank like this, but they have to come to your site and post good topics and take care the discussion goes along etc. It might even be a socializing exercise in tricking the posters to type the tags you've specified! Cause they are not visible to the public.
And here comes the reality check part. I've been just "hacking around " with this thing and I'm aware things should look prittier than they are now. First things first, it requires the ra_custom_profile_keys plugin as an easy way to add a field in the registration. Which is not a so bad thing after all. Good plugin. But more importantly I needed a way to hide the tags field in the profile view and I only managed to do it by modifying one of the template-functions, which I know is absolutely an ugly thing to do, even if I just added a line.
It's all in the code
and you can see it in function here. (I was hunting for a marketable domain name, sue me).
Btw, if you happen to try it out and things go wrong... I really hope I could help you about it but don't hold your breath.
Ciao