I've had the Canon S2 IS camera for several years now. I first became interested in the camera when I was looking to upgrade from my Canon G2. One of the first features that jumped out at me on the S2 IS was the huge 12x optical zoom with image stabilization. That's huge and it's useful.
One downside to that large zoom is that the camera can have a real hard time focusing at that full zoom. The camera requires quite a bit of light to focus at that length. Though it has a green focus assist light, it doesn't always work that well.
The camera is quite versatile though. You can put it in Shutter Priority, Apeture Priority, or even Full Manual mode, making the camera very handy for capturing creative photos. I've recently used the manual focus feature and was pretty happy with the results of adjusting my depth of field that way.
One clear negative of the camera to me is the lack of Camera RAW support. Serious photographers are the only ones who will really need this feature, but I wish it had it.
The battery life is superb and the fact that it can use standard AA batteries turned out to be a much greater benefit than I thought. I reccommend getting yourself some high capacity rechargeable batteries like Energizer. They work great for me.
Overall, I think this camera is easy to use, versatile, a good value for the money and for the most part, takes great pictures.