Elektor had a little project to read IR data and I think the download was free. I dare say it was in the last two years maybe?

Michael's technique is a common one, another way is to sample the IR input at a regular interval (normally 4 times the smallest bit width) and use software to detect the edges and count the widths. This has a fairly high overhead in terms of cpu usage.

The two major IR codes seem to be Philips RC5 and the NEC code. The Atmel site has a app note for decoding RC5 on an AVR but the techniques remain the same regardless of the cpu chosen. Might be worth checking the Microchip site also (even though I despise PIC's!).

Expect to have much fiddling!