Check out the December 2007 "Men Of The Year" issue of GQ.
If you go to page 318, you'll see a picture of the quite attractive singer Rihanna over Robin Thicke's lap with Robin's hand allegedly getting ready to swat her. In that same issue, there's a great shot of the actress Drea De Matteo in a "ready for spanking" position on page 202 also.
It's been awhile since I've seen a posed spanking shot in a mainstream magazine.