Hmm... here is a tablet PC that may be worth considering for someone who tends to break their N8x0 due to dropping, water, freezing, (you name it...) and if you also want a phone with it:

http://www.ropermobile.com/products/duros/

Price is likely preventing most regular people buying one...

It runs WinXP, Vista or Linux... so most people would find what they want...

Seriously, I do not think it is competing same market (=pocketable computer) than N8x0 series, but more with ultraportable PC's for harsh environments.

Hey, I like it! For me that would be Just Another Handy device, not a replacement for anything I currently have.

while it does not help againt extreme temperatures or falls, this may be a good bet against water:
http://www.aquapac.net/ukstore/erol.html

i have one right here, and the N800 fits nicely

one can even use it while its inside.