Galaxy S3, Lumia 920 and iPhone 5, 100% Scalable Photoshop vector.
Mobile Flagships with PSD is a free Mockup design resource made by Dribbble user Bluroon. As far as I can tell, its license is Unknown.
Helpful hint: Dribbble users are nice. If the license is unknown, it is usually because they forgot to mention it explicitly; not because they were being stingy. Ask nicely and they will probably allow you to use it.