A previous deal like this was posted by arriaga about 7 weeks ago but Clintons are now re-introducing this saving of £5 on a £25 iTunes gift card for one week from Monday 16th February 2009 - as I understand it this will be instore only.
Please note that I have this from a very reliable source.
LISTEN UP! iTunes Gift Cards give you, or the music lover in your life, instant credit on the worlds number one digital entertainment store the iTunes Store. iTunes is a store, a player, and a way to load music and entertainment on to your iPod or computer. So strike the right chord by giving the gift of choice.