When I first received the N800 for trial, it had an older version of OS installed (I can't recall what version) which was VERY buggy. Specifically, it would have some major hiccup issues with usernames and passwords. For one particular site, I accidentally saved an incorrect password, and it absolutely would not let me manually enter the correct one: I had to go to the options and clear all my saved passwords. However, I flashed the latest OS2008 onto it, and that seemed to correct these issues.
In general, the device is pleasant to use. It feels great in my hand. The sound effects are cute, not at all irksome like some default windows sounds. It was really convenient to use while I was sick on the couch, and unable to rest a laptop on my lap/stomach. My brother in law and I had particular fun with the marble game; we spent a whole day passing the N800 between each other, attempting to solve new levels. I was also able to open up pdfs of journal articles that I wanted to read and peruse it on the train to school.
There are a few fundamental issues that detracted from the utility of this device. The main thing is that it requires wireless, which is not always accessible where I live... even in Mountain View, GoogleWifi just flat out sucks. The majority of the places that I could connect were places where I already had access to a computer. If the N800 connected via satellite, its utility would go way up. The other limitation was it's input method. Ultimately, I found myself frustrated by the touch keyboard and the handwriting recognition. Perhaps it is me, but those types of input are too slow. Having a keyboard would make text much faster to input, and increase the N800's potential as a communication device away from your computer. Additionally, while the little webcam is super cool, I ended up not using it because the one person I know who uses video chat uses MSN, which I don't think the software could connect to.
conclusion: The N800 is great for opening up pdfs when you have wireless access, then keeping it open and reading stuff on the train. It's good for surfing by clicking. Because of lack of button keyboard, it's not so great for communication unless you're better than I am at touch keyboard/writing recognition. This device would be more awesome if it connected via satellite. It's certainly a fun toy, but needs a few improvements to be a truly versatile tool.