Flickr rated the percent of users that uploaded at least one photo to their website from the given camera phones over the last year and compared the results. The graph has been "normalized", which means they account for the fact that people join or leave flickr every day, so it represents each device as a percent of all other cameras.
They also note:
"The graphs are only accurate to the extent that we can automatically detect the camera used to take the photo or shoot the video (about 2/3rds of the time). That is not usually possible with cameraphones, therefore they are under-represented."