I've given it 10days, had fun, but have decided to return my N800 (CompUSA are great!).

My original requirements were:-
1. Portable (fits in pocket)
2. WiFi (reliable connection)
3. Decent resolution screen (better than 320x240)
4. SD card (preview stills/video from digital cameras)
5. Email/Contact/Calendar (preferable sync with Outlook)
6. Bluetooth (GPS/ cell phone xfer)
7. USB Host (external Keyboard/camera/drive)
8. MP3 playback
9. Reasonable battery life

The N800 fails to deliver for these reasons:-
1. I struggle to safely take it out of the house. No hard shell like 770. Just too awkward for a pocket (I could throw my Jornada 540 around and it is still going)
2. WiFi just does not connect correctly to open APs. I frequently get 'connected to xxx with link-local IP address' and browser/email fail. It does work well in my house though.
3. The screen is excellent!
4. Great having SD card slots, but I still can't preview my camera video AVI files
5. Maybe one of the PIM apps can do this/will do this?
6. Bluetooth works fine, although I didn't see any A2DP/headphone profile. I can't seem to play audio through my bluetooth earpiece I use with my cellphone.
[[7. Rumour is USB Host Mode is disabled in the kernel. IS THIS TRUE?]]
8, 9 no issues.

In summary, half my requirements are not met. I will probably replace it with a VGA, WiFi, SD Slot, Bluetooth, Windows Mobile PDA (eg Loox C550, Acer n311, Dell Axim X51v) for the same price, my belief being one of these will fit my requirements better. I will miss the lovely N800 screen!