TechCrunch has the scoop on the launch of AlertThingy, an Ajax-based desktop client built on Adobe AIR for tracking FriendFeed. I haven't bought totally into the FriendFeed thing yet, but the application is really clean and may make it easy for me to track what people are doing on the service. Twhirl was great because it was a better way for me to use Twitter. AlertThingy may be the path to actually get me to use FriendFeed.
You can comment directly from the application and it links directly to the content if you need to take a closer look. Having to use the "remote key" instead of my username and password is a little odd but AlertThingy links directly to the page you need so you can get it quickly. We talked to the guys from AlertThingy at our on AIR event in London and they said it took longer to get the certificate from Thawte than it did to actually build the AIR application.
The other application recently released is a FriendFeed application built on WPF from Sobees called bTittleTattle. It's Windows only but it's part of the entire Sobees application suite which has a number of mini applications that you can use. I have a beta account for Sobees and I like the interactive, fun, interface but I think it's targeted at a different kind of user than something like AlertThingy.