The problem with most Irda hardware is that they are designed for short range usage. I have had good luck with the RedRat2 serial port based learning remote control. It's about the size of a normal remote control device and I have mine hooked up to my desktop machine to control my A.V stack(DVD/VCR/PVR/TV/...).
Here is a link to the web site:[Link: dodgies.demon.co.uk]
I have written a bunch of Linux software for it:[Link: slip.net]