I really hate to help BP in spreading any information of compromised integrity, but this video, which describes how the company has started using Kevin Costner's oil separating centrifuges, is pretty interesting.
[youtube]http://www.youtube.com/watch?v=C9-e0TfwrIc
And here's your grain of salt to go with the video: At minute 1:40, Lance Ortemond says that they haven't yet gotten the concentration of oil in the separated water down below 15 parts per million, and it sounds like that means they aren't able to discharge the separated water overboard, which may explain why the video doesn't show the barge at sea at all, and makes you wonder what they do with this slightly oily water. Moreover, with only one of these barges, it looks like a relatively small (and, like I said, only relatively well-functioning) part of the cleanup effort.