I've been playing around with Skimmer - a free desktop application that collects the activity of your, facebook, twitter, flickr, youTube, and blogger accounts and lets you both read and post to each of them from one handy location.
Skimmer was developed by a Minneapolis ad agency, Fallon with the help of Sierra-Bravo, a Twin Cities web development company. Fallon wanted a way to share what their employees were thinking about, so they developed skimmer, which in Fallon's case allows their employees to publish their tweets, pics, and posts to the Fallon stream in addition to the other locations. As Fallon talks about it, their people are what make the difference.
The interface is nice and clean and is relatively easy to use, although I'm still working out all of what it can do. I like the idea of having all my social network tools accessible from one space and I hope Fallon or Sierra-Bravo continue to develop this.
I would love it if it was able to interact with blog tools beyond blogger (by blog is on Movable Type). I also haven't found a way to post comments to other people's posts. Still free is free. Try it out you might like it.