I picked up a pair of wireless controllers for my ps2 at argos (UK)for £2.99 (Originally £19.99) link click here. Not a bad deal I think. They are made by QuickShot and run on 4 AAA batteries.
They are not the offical sony ps2 controllers but they work pretty good. Also the D-Pad is like the old sega mega drive controllers and not built in under the plastic like the sony ones, comes in handy for certain games when you need more manourverability so thats a good feature in my book!
You can also get product replacement cover for £3.99 if you wish which covers them for 5 years (I forgot it states 3 years, but I sweet talked the lady into 5 year cover for the same price) so if they go bust you can get them replaced or refunded. If refunded your only £1 out of pocket so I think its worth it in my opinion. I had a £5 voucher to use anyway so it wasn't a deal I could pass up on.
Also the 7day shop is having a sale on Eneloop rechargeable batteries (which in my opinion are the very best brand you can get, they last ages) which are the newer generation and last longer than the old ones. Theres info on these batteries in reviews on amazon and the hotukdeals website if you want to read up on them and see if its worth it.
Edit: Note: Il try and upload a picture cos the one they show is slightly different.