PC World will match amazon's price for any item.
I got a 80gb ipod classic for £140.97 - and PC World have currently got an offer on for a free Belkin case with any ipod classic or nano purchase. This has a value of £24.99!
Weirdly, and unexpected really, they will give you this, regardless of the price match. I also believe I was entitled to 10% of the difference, but as this amounted to around £1.80 I didn't bother to query it!