I'm currently working with a Flickr contact, Pierre, on a shared blog. We're not really sure what it's going to be yet, but it's nice to have someone to work off. He's in France, and I'm here in the UK, so it's the perfect balance of independence and collaboration.
The link is here:
UPDATE: We've just added another friend of ours, Jiro to join the blog, so we should be seeing some great work.