Clearly from watching these stats about cameras used on Flickr Canon and Sony Ericsson rule. Canon is totally dominating the usage of Point & Shoot cameras which doesn't surprise me. Even if I'm a Nikon user I still recommend the Canons for Point & Shoot if people ask me.
By far, the most popular SLR is the Canon EOS Rebel XT as you can see. It doesn't surprise me that much. It is a great camera. I had sort of hoped that my camera, the Nikon D70, would be more popular but perhaps it doesn't really matter.
Another interesting observation is how cool pictures people take with the Sony Ericsson cameras. It's amazing what can be done if you're a bit artistic. Most of those pictures are much better than mine taken with my much more expensive D70. Pictures taken with the Sony Ericsson 750i and the Sony Ericsson K800i