micromobs lets you create build group discussions around a topic or social group:

Once you sign up and join a group, you’ll see all of the activity shown in a Facebook-style stream. Messages can have links and photos attached to them, and you can search through messages if you’re trying to find something in particular.

The most popular topics and users are shown in the sidebar, which is a great way to get a feel for a particular mob when you first arrive: it makes it easy to figure out who’s the most prolific and what the topics of conversation tend to be. It’s a little thing, but it really helps.

micromobs has a lot of personality and a lot of potential. Their front page is positioning them as a good fit for a lot of markets, and I can actually see it working for many of their use cases. Let’s hope they get some traction and take off, because it’s a already nifty product.

Follow them at @micromobs, or check out their blog, wherein they chronicle the experience of bootstrapping and launching a startup.