Nebul.us is an online application, currently in private beta, that aggregates and visualizes your online activity. Enter your information for Twitter, Facebook, Flickr, etc and install a plugin in Firefox to record your browsing behavior. Get something that looks like the above, sort of a donut-polar area chart hybrid. Nebul.us calls it a cloud.
While your personal cloud can be interesting to a small extent, the strength of Nebul.us will most likely come out of the social aspect. There's a social cloud to see your friends' activity and then there's a public cloud that lets you see what's trending across the network.
This of course depends on how many people use the service as well as what those users select to share. Right now, for example, the public cloud (above) isn't all that interesting. I see people are going to Twitter, Google, and Facebook. Nothing new there.
Finally, as with most of these types of things, we always have to ask, "Does this visualization do any better than a simple list?" As it stands now, no. The cloud isn't really doing anything for me. If I see something interesting, I'll just bookmark it on del.icio.us or tweet it.
But hey, they're still in the very early stages. There's a lot more work to be done.
Watch the clip below for more: