This tip is only for devices running webOS 3.0.5 or higher

In addition to adding Bluetooth keyboard shortcuts to allow copy, cut and paste in webOS 3.0.5, you now also have the ability to navigate through your open cards while in card mode. While you always had the ability to minimize your application to card view using the  key on the Bluetooth keyboard, you could never move between them, nor re-focus on any of the apps to bring them back to full-screen mode.

With webOS 3.0.5, you can now use the right and left arrows keys in card mode to highlight the next or previous card. This even works with Stacks, as the webOS update now grays out the apps that are not in focus so you can choose which card in the stack you want. Once you find the app you want, just press the "Return" key and you will be brought back into that app.