I bought a 1gb Kingston mmcmobile which is slower than the ATP 133x stuff but was $65 and has a lifetime warranty.

Since the 770 doesn't transfer any faster using either of these cards I figure the extra speed wasn't worth the extra $$. The only time I use the speed is using a external flash reader.

I can't find on the forum where, but someone benched marked the stock 64mb card with a faster aftermarket card at the transfer speeds were pretty limited. Using my flash reader with my 1gb card it blows the off transfers when compared to transfers to the card inserted in the 770.