I just wrote my first plugin for WordPress, and it needs testing. I don't have a huge amount of free time to test, so I'd love if people could tell me what they think. So far I'm sure it works on WP 2.0...
Anyway, Expand Comments is a plugin that uses AJAX to provide a blog with a link on the bottom of each post. When the link is pressed, the comments (read from the RSS feed) will be appeneded immediately below the post, without any page refreshing. It really speeds up the reading of a site, and also gives it a sexy feel. The comments can then be hidden by clicking the same link. Each expansion/contraction of a comment section is only downloaded once. after that, CSS just hides/displays the comments.
to see a working demo, go to my site: http://nymb.us
You can find a bit more info + download at http://nymb.us/?page_id=45