I got the 8GB ($39.99 Transcend) and the 16GB ($70 ADATA) from newegg (Both class 6 SDHC cards), I got them earlier this week and have had no problems with either of the cards nor do they seem to drain my battery any more before. You dont get quite the full 16GB after the card has been formatted but it is great to have close to 24GB's of storage in my n800. I highly recommend buying as much storage as your device is capable of as its so cheap. To prolong my battery I also picked up a Tekkeon Tekcharge MP1550 which is an external battery which is compatible with the n800, should take my n800 from around 3 hours of media playback to 3-4 times that!

Get the $16GB, its worth it for the price!