TinyFeed is a WordPress widget which loads a microblog status feed via Ajax. It is currently restricted to microblogs with Twitter-compatible APIs, so only Twitter and Identi.ca.
I wrote it for one reason: I think the default RSS feed WordPress plugin is lame. I didn’t like PHP retrieving the feed and having the page wait to load because of it. Even though it caches the feed, for frequently updated feeds it just doesn’t make sense. Loading the feed via Ajax shaved seconds off of my page load time. I was so immensely happy with it that I decided to widgetize it and share it.
The current release of the widget is also the first, so there may be a few bugs to work out. But I also use this personally, so it should be stable enough for normal use.