If you're an Android user who also owns a PlayStation 3, you may want to check out a nifty creation out of XDA called BlueputDroid. It's an application that allows you to use your rooted Android device as a Bluetooth keyboard and trackpad for the PS3. While there are similar Android apps to pair phones and computers, this seems to be the first that's compatible with Sony's gaming console.
BlueputDroid is currently available for free in the Android Market for select devices. It's labeled as a beta, so you can probably expect some bugs. Head over to XDA-developers to view a list of supported and unsupported devices, as well as a short guide on how to set it up. See the app in action in the two videos below.
Note: if you're using an app to block ads, you will have to disable it to get BlueputDroid to work properly.