Great Tool for Product Placement (designs,apps,etc) (pics)
 

Found this the other day.

http://placeit.breezi.com/

bascially just create your screenshot, drag and drop.

http://i.imgur.com/MMKI4h.jpg

http://i.imgur.com/krCJRh.jpg

http://i.imgur.com/1dYSDh.jpg

http://i.imgur.com/tTJ3Gh.jpg

http://i.imgur.com/2Ry2Oh.jpg

hope someone finds this useful.