Android only: Gmote controls your desktop PC directly from your mobile phone, letting you control playback of music and movies, browse your file system, or even use your phone as a keyboard and mouse.
To get the media playback controls working, you'll need to make sure that your PC has VLC installed, install the Gmote server application — there are versions for Windows, Mac and Linux, and then install the Gmote client on your phone. Once you've completed the setup, you can connect the mobile client to the Gmote server by IP address and start controlling your PC from your phone.
It's definitely not a substitute for a good media centre remote, but it's a great way to control a PC using your Android phone. Hit the link for the download, or check out the How-To Geek guide for a screenshot tour of how it works. Gmote is a free download for Android, Windows, Mac and Linux.