I've been with RedBubble for a few months now and, so far, it's been a good experience. Much as I suspected, it's turned out to be far more useful than Photobox.
One of the things that happens a fair bit there is that people will work together on collaborative projects. It's not something I've really looked into myself (although a friend and myself have knocked a couple of ideas about but haven't had the chance to do anything yet) but I've always been intrigued by the idea.
About a week ago Lloyd Harvey commented on my photograph Beyond the Trees, saying that it reminded him of one of the early scenes of H. G. Wells' book The War of the Worlds. He then went on to express a desire to take the image and turn it into what he was seeing.

Click on image for bigger versionGiven my interest in doing some sort of collaboration, and being a big fan of the book (I read it many times as a child and own quite a few copies), I was intrigued by the idea. So, a couple of BubbleMails later we had a plan.
Lloyd delivered
the result to me yesterday:

Click on image for bigger versionI think he's done a great job (and I do like the idea of a tripod getting ready to take on
Billingborough) and the bulk of the credit goes to Lloyd: I just took a photograph, he did a lot of work creating the tripod and then processing the final result.
Have a look at
his page for the image for details on how he created the work. And be sure to have a look at
his website too.