I've contacted the manufacturer of the male mini-B to female A USB adapter that I mentioned earlier in this thread. I'll keep you guys posted on what I find.

Sounds like what I'm looking for is a mini-B that has the ID pin shorted to ground (instead of floating). This triggers the OTG feature of the N800's USB port. Technically, this is a mini-A connector, but "mini-B" seems to be used as a generic term for the connector. If anybody has recommendations of plugs they know to work with the N800, and are <$5 with shipping, please let me know.