Was shopping for some PSN credit this morning, in anticipation of Dead Nation, BFBC2 Vietnam expansion and Castle Crashers - which should all be here before Christmas.
Anyway, the best price I could find was at The Hut, using the Walkers Crisps 10% voucher code - this is pretty easy to claim and redeem.
You just need to sign up at http://www.walkers.co.uk
and claim your 10% off The Hut voucher using the 2 points you get for signing up.
Quidco has also tracked at 32p - which isn't a lot, but it all helps, I guess.
I hope this is of help to someone.