I've been playing Project Gotham Racing 4 now since February 14th (thanks honey) and just recently began taking photos. You can pause the game at any time and snap a picture from any angle. It's really quite amazing and the quality is equally as good.
You can take pictures anytime during the game, but I setup a custom race so it would be a location, track and weather of my choosing. Once I found the right spot, near Big Ben with the London Eye in the background, the Aston Martin DBS speeding through the rain soaked streets, I paused the race, found an esthetically pleasing angle and snapped my photo. Once it was uploaded I went to the PGR Nations web site, logged in and downloaded my picture.
Larger picture here.
It's now my current wallpaper, but I'm working on more. Time for some good Z06 pictures.