uICE

From MediaTexX:

The universal Infrared Control Engine enables complete control of your Windows system with handheld infrared remote controls. Ever missed a remote control to watch DVD or listen to Winamp music from the sofa? Looking for an easy way to slide through your Powerpoint presentations from the distance? uICE is what you need.
uICE comes with support for a broad range of remote control receiver devices, as well as a large set of actions for all common Windows procedures such as executing/closing applications, simulating keyboard input, adjusting sound volume, shutting down the PC, and even advanced functions like sending API messages to applications. Many preconfigured action sets are available for applications like DVD players (e.g. PowerDVD, WinDVD), DivX players (e.g. Windows Media Player, BSPlayer, Zoom Player), TV viewers (e.g. MoreTV, WinTV, BorgTV).
The current version supports Hauppauge WinTV, Creative Live!Drive/AudigyDrive, IRMan, UIR, WinLIRC, Realmagic Hollywood Plus, Packard Bell Fast Media, Anir Multimedia Magic, Logitech/AST/IBM and many more. Using a plug-in technology for hardware access, the software can be easily extended to support any kind of remote control receiver or other input hardware. With its built-in TCP/IP server, it is even possible to develop client applications with native remote control support without accessing the hardware itself. Look out for our Winamp plugin, available at our website, which makes use of this technology.