As part of its Creative Suite 5.5 update, Adobe has released three Adobe Photoshop Touch apps for the Apple iPad: Adobe Color Lava ($3), Adobe Eazel ($5), and Adobe Nav ($2). You can grab them now from the Apple App Store.
The Adobe apps were developed using the Photoshop Touch Software Development Kit (SDK) in order to demonstrate the potential for new interaction between Photoshop CS5 and tablet devices. Adobe has already hinted that more Photoshop apps are coming and that it wants developers to create their own apps for Android devices, the Blackberry PlayBook, and iOS devices.
For the apps to work with your copy of Photoshop CS5, you have to update (don't worry, it's free) to version 12.0.4. For those who don't own Photoshop CS5, the updated version (version 12.1), which is part of Creative Suite 5.5, will also enable the Photoshop Touch app functionality.
The above is a step-by-step video to walk you through updating Photoshop CS5 to version 12.0.4, enabling Remote Connections, and connecting each of the Photoshop Touch apps to Photoshop. If you'd prefer individual videos for the apps, Adobe has uploaded those to YouTube as well: Adobe Color Lava, Adobe Eazel, and Adobe Nav.
For those who aren't as visual, here's a short description of each: Color Lava allows you to mix colors on the iPad using your fingers as well as create color swatches and themes that can be transferred into Photoshop, Nav provides more desktop space by enabling users to select and control Photoshop tools on the iPad, and Eazel lets you create paintings with your fingertips, which you can then transfer back to Photoshop wirelessly.