Using Supersaver Delivery you can get this matched pair of 1GB RAM modules (useful for dual-channel set-up which I use them in) for only £29.57 delivered. It has been on previously for over £31 from what I remember so hopefully those that missed out that time can get their hands on it this time.
User reviews are good and from my personal experience of it in my dual-core PC at home has been great. Stable RAM and works dual-channel no problem.
Description: 2GB 667MHz DDR2 Non-ECC CL5 DIMM (Kit of 2)
Detailed Specifications: Standard 128M X 64 Non-ECC 667MHz 240-pin Unbuffered DIMM (SDRAM-DDR2, 1.8V, CL5) (Datasheet)
Mfgr's System P/N's: N/A
Form Factor: Memory Module
Spec Sheet: http://www.valueram.com/datasheets/KVR667D2N5K2_2G.pdf