I had some fun creating this new iPhone 4s Mockup (you can use this as an iPhone 4 mockup as well, they look the same) and I wanted to share it with you for free.

The picture is super high quality (3000x2250 px) and the screen is editable. There are a couple of effects on top of the screen so it won't look flat. The hand is cropped out of the picture (transparent background) so you can replace the background with anything you want (even scenery pictures).

The file is in PSD format and the design can be replaced with your own by using the included smart object layer.