The best feature of this app is that you can set the notifier to only display updates from specific groups. Thanks to this, you can set up a Friendfeed group with your high-priority feeds or populate it with only your closest friends on the service and receive instant updates when they post or comment on something.

Friendfeed already gives you real-time notifications over IM, which also let you comment on items from your IM client through a small set of very easy to use commands. The notifier also allows you to comment on an item, but sadly, the app takes you to the Friendfeed web site to do so. You can, however, like an item right from the pop-up window on your desktop.

As with a lot of real-time notification services, the amount of updates can quickly become overwhelming and distracting. Being able to restrict updates to certain groups is nice, but it would be great if FriendFeed also gave you the option to only see certain types of items (blog posts, Google Reader shares, etc.) in your real-time stream.

It would also be great if you could set a persistent search and then get real-time updates from across the Friendfeed network whenever somebody uses a certain keyword. It is pretty clear that search is becoming one of the key features on Twitter, and Friendfeed, even though it has fewer users, aggregates a wider range of content, though it is currently not really doing a lot with this data.