Photoshop mockups are layered photographic files that allow you to insert your own website design drafts into photo-realistic computer settings. It's a great way for web designers to showcase their work in a unique way. I used a mockup from Mocup to highlight a screen grab of my home page in the photo above. You simply paste a screen grab of the website on a layer in Photoshop and use the skew took to make it fit the angle of the computer in the mockup.
Mocup is a wonderful resource for achingly beautiful layered Photoshop mockups at very moderate prices. Plus, they have a collection of free mockups that are quite beautiful as well. Check it out! -Don Peterson, Freelance Web Designer