Apple's iPad isn't available yet, but that isn't stopping developers from working on building apps designed for the tablet form factor multimedia device. Mocking up an interface for an iPad app, however, doesn't require Apple's developer tools or a membership in the company's developer program thanks to a couple slick templates for Photoshop and OmniGraffle.
The iPad GUI PSD for Photoshop includes a wide selection of interface elements in vector format along with a screen template set to 768x1024, so you'll be able to port mockups into the iPad SDK later without worrying about whether or not each element is sized correctly. The collection is free and available for download at the Teehan+Lax Web site.
iPad GUI PSD
The iPad Stencil for OmniGraffle from iA is based on iPad GUI PSD, but is set up as a stencil file for The Omni Group's OmniGraffle. Like Teehan+Lax's version, the elements are vector graphics, so they can be resized without losing image quality. The stencil set is also free, and can be downloaded at the iA Web site.
iPad Stencil for OmniGraffle
Sure, Apple's iPad SDK is just a download away, but both of these templates are easier to use for mocking up an interface. They're also great options for designers helping to create iPad app interface layouts, but aren't involved in the coding process. They can design in applications that are more familiar, and hand off the mockups when they're done.