If you are into social sites, check out the newest for OSS: Open Source Universe.
I like this because it seems to me that most people in OSS (developers, designers and even users) tend to cluster around projects. I mean, that makes sense when actually working on the project but mixing with other projects (on a regular basis and not just at the occasional conference) makes sense. If there is regular social interaction, I think that will trickle down to ideas which would make for even better products.
Of course, this isn't just an issue with open source. Technologists seem to want to spend most of their time with people dealing with the same technology. Who today isn't using (even if not developing) multiple OSS applications and tools? On a daily basis I am moving between PHP, MySQL, Postgres, Linux, FireFox, and a plethora of other tools.
So anyway, that's why I wanted to give a shout out to OSU. Now, having said all that, it's a new site and there just isn't much there right now. The forums need help. I don't like the fact that the forum is grouped around project. If I wanted to just hang out with Drupal folks, I would go to the Drupal forums. I think the forums should be grouped by technology. Let database folk hang together, let the PHP, Perl and Python folks hang out in the Language forum, etc.
The link exchange is a but cheesy for my but they are already listing some jobs.
If you don't already have a blog, you can start one. I would rather start one on blogger or wordpress though.
So, give the site a check and maybe post something in the forum.