The Sony W80 and W90 are by far the easiest of the newer cameras to hack. I have bought three W80's on ebay for under $100 including shipping. You can find information on hacking these cameras on the Pixcontroller website. I am working on a W200 right now, but it has turned out to be somewhat of a challenge. I hope to have this camera finished later this week.
GPo, The flash is about the same as the W35 and W55. The W80 and W90 are the first of the new Sony cameras that use the new Bionz image processor. This new processor makes the cameras a little faster than the 35 and 55. They are much easier to take apart and hack.