Late last year in 2012, someone had launched a site that let you upload screenshots (or any image really) and it would embed them into nice stock photos of a Apple phone, tablet or laptop/desktop. It was basically designed for someone making a product web site and wanted to feature shots of the app or web site running on those devices. There was even a shot of a person holding an iPhone in their hands.
I can't for the life of me remember the name of the site though, and googling isn't helping me. A friend thinks it might have the words 'showoff' in it, but no luck either with that phrase.