http://www.backcountry.com/store/HAR...Flex-Case.html
Don't know if this has been mentioned yet but this Harmony PDA case fits the N800 like a glove and provides a water proof bag that you can use the N800 through easily. There is even enough room for my iBlue GPS module to stay dry at the end if you use one less fold to seal the bag.
The only problem with it is the padding makes the upper edge button hard to press.