Signed up to Webpaint, Web 2 Oxford Libraries, with my Facebook account.
I didn't find the page layout attractive - the ads are distracting (especially the one that pretends it's your inbox containing a new message, only it turns out it's a MacBook ad. The price for a free resource, I guess).
There was a page about Facebook where it was suggested that one can add a SOLO widget to a Facebook page. I thought it might be fun to add one to my personal page. However, when I found the application and followed the Wiki instructions to click the 'add it to my page' button, a window opened but without any obvious way of selecting my - or any - page to add the app to. So I don't know what I was doing wrong there. I also tried adding a 'droplet' - in this case a widget that shows updates to the wiki. Again, something went wrong: Clicking 'Get the droplet' gave me the opportunity, not to get it, but rather post about it on my wall. When I clicked this link there was a failure to go to the link for some reason.
I haven't yet found a substantial contribution worth making. Just to get an experience of editing a page, I did correct a typo! I have had some prior experience of Wetpaint, though. A philosophy group I had some connections with (it was run by the philosopher who taught me when I lived up North; I used to help tutor groups sometimes) set up a Wiki for their reading group. I signed up and make some contributions to their discussions. It looked like a very useful tool for greatly enhancing distance-learning.
My supervisor (also a 23 Thing-er) created a Wiki-space for our reserve (Bodley Lower Reserve) - screenshot above. I became a member and we created a discussion topic. Actual reserve-work prevented us pursuing things further, but I can see some potential there for facilitating discussion on how procedures might be improved, etc