The Elgg guys have been launch-tastic at the moment: the Elgg support community for the developmentally-minded has had a makeover, Elgg 0.7 has been turned loose, there’s a new documentation wiki (using the Elgg-MediaWiki integration plug-in which Dave has been busy making pretty) and (although currently also only over at the developer community site) there is a new forums plug-in.
In addition they’ve been working on Explode! over the weekend, a new social networking ap/hack which is currently in pre-widget form, but still around a thousand times more useful/fun than a lot of other social network projects. Explode currently "allows you to create a friends list, wherever they might be, and display them on your website, a sort of distributed friends network". Basically a very cool ap that lets you hook up with friends across a social networks. I’m betting on some pretty swift developments.
You have to set up an account over at the main site, and then paste a line of code into your blog/site. I managed it pretty easily with Typepad (although you have to use an advanced template until the widget becomes available) and Blogger, which was a breeze.
I had no luck at all (surprise surprise) with MySpace While I’ve been typing this the boys have just released their first MySpace-friendly graphic widget! Once on your site, the widget enables people to click-to-add you to their network.