Last night I released my latest app, called PC Keyboard.
It's for those times where you're sitting at your desk with your PlayBook and you have something of non-trivial length to type. You simply open the app, and then start typing on your PC keyboard. What you type is displayed on your PlayBook and copied into its clipboard so that when you're done typing, you flip back to the PlayBook app you were using and Paste.
My Dad discovered a great use case this weekend, which is for those people who only get their work email on their BlackBerry (and thus their PlayBook via bridge). If you need to type a response of any significant length on the weekend (or evening), it is much faster to type it out using your PC keyboard as opposed to your BlackBerry. Bingo, PC Keyboard saves the day. This implies that the app would also be extremely useful as a phone app for those that don't have a PlayBook.