All that needs to be done is to open a photo on the Flickr website. You notice the information that are posted on the same page like comments by other Flickr users or groups the photo has been added to. If you scroll down the page you will eventually come to a section called Additional Information in the right sidebar of the website.

This section contains information about the location and date the photo was taken, the number of views and the digital camera. The Taken With A [digital camera model] row will provide the information for registered users and guests alike. This seems actually like a very good way of researching a digital camera before purchasing it. If you got a few models that you would like to compare you can go to Flickr and check out the Camera Finder section of the site.

This section lists the most popular cameras used by Flickr users and provides information about many other digital cameras and brands as well.