Superquick SDHC (not SD!). Have received mine from these guys and must say it loves up to the over 20MB/s (read) spec. Wrote a 175MB file in around 20 seconds (write spec ~10MB/s).
Fantastic - why buy a (only marginally) cheaper class 2 SDHC card when they write at 2MB/s!?http://www.cpu3d.com
forum members get free p&p if you have over 50 posts. Free p&p applies to anything at specialtech, so pretty worth it!
Otherwise cheapest postage option is Royal mail recorded (£2.49) which brings price to £ 35.26
Product Name PEAK 8GB SD CARD 2.0 SDHC CLASS 6 RET
Model Number 214054FBPK
1 Year with Specialtech.co.uk 4 Years with Manufacturer
Interface Secure Digital
Read Speed 22.5MB/s
Write Speed 11.84MB/s
Operation Voltage 2.7 - 3.6V
Special Features Error Correcting Code (ECC)
System Programming (ISP)