to be honest there are better card than the R4 - i had this and found it would not support SDHC cards and will only support upto 2gb SD cards.

I got rid of my R4 card and bought a nintendo edge card which can support upto 32gb SDHC cards.

http://www.pinpointgames.com/nintend.../prod_112.html

or

http://www.digizo.co.uk/Edge-Card.191/

I recently ordered one for a friend from amamzon with a 4gb card for 32 quid delivered