With this simple IR receiver you are able to take command of your computer from across the room using a simple IR remote control and WinLIRC. Best of all the receiver should cost you less than $15 to build.
“WinLIRC allows you to transmit and receive standard infrared remote control signals. This allows you to control your computer using almost any standard infrared remote control. It also allows your computer to control other equipment which uses these signals (stereo equipment).
WinLIRC is the Windows equivalent of LIRC, the Linux Infrared Remote Control program. WinLIRC (through version 0.6) was originally written by Jim Paris. Later releases are written and maintained on sourceforge.”