I have a 4GB card from Grassroots. It works fine in the 6700 but be aware that if you want to use the camera you must have less than 2GB free space on the card.
The problem I am having is that the card is not very reliable in USB adapters. I have to put the card in it's SD adapter and then in my Sandisk USB adapter in order for the card to be read at all. Once in a while the files that I transfer to the card disappear when I try to read the card the second time. I have to have to recheck to see if a write to the card was successful. I've never experienced this kind of thing with a memory card before.

Last, Grassroots is a pain to work with if you want to get an RMA and return the product. They are still giving me the runaround when I asked for a refund.

regards

Allen