Hi Tom et al,
I've made a video showing fitting a Deal Extreme wide lense to a red lense v2 camera. Because the red lense (B lense) is a little wider you have to virtually remove the front of the case to avoid vignetting even with the 0.67 lense. The fisheye is pretty much unuseable.
It also shows some good detail about reassembling the camera, fitting the board etc. And shows a lense comparison.
Feel free to add it to the FAQ's or elsewhere.