I've never used an aggregator before.  I thought it would be cool to have a little box on your desktop that alerted you to something you subscribed to, but all I find are things that look like email clients.

Is there such an aggregator that does the following?.......

One that pops up a toast message - much like MSN Messenger - when something new has happened.

Scenario:  Your waiting for a reply on a forum, or waiting to hear of any new posts on a forum.  Your working away and 'pop' a toast pop-up appears and lets me know that someone has posted something new.  Or say, scoble has another video posted up on channel 9.

Anyone know of such an agg'?