as USB charger for... the 810? or for other gear you are carrying around?

My own "business use" never involves writing word files, so no problem there. I write a lot of other stuff though, so I bring my foldable BT keyboard, and a travel router, and an M1200 Holux GPS (which incidentally works fine also with my Palm T3+TomTom, which I use if I need to do real car navigation). With this I'm very well covered for almost anything.

Now, if I could just load up presentations to an SD card and wirelessly run them from my N800.. there's probably a way (some of the earlier discussions got us _almost_ there..).

GPS is not affected by clouds, at all. It was designed to work regardless of the weather - the war doesn't stop just because it's cloudy. Liquid water, however, will block the signals entirely, and your body is mostly salt water. Your fingers, hands, or head, or torso between the satellites and the antenna will completely block the signals. Metal will also block them, as well as the coating on some windshields. GPS doesn't work well indoors, inside cars, or under/behind your body, and that's not just a problem with the N810, it's a limitation of GPS in general because of the frequencies used.

Still, there's an enormous difference between older GPS chipsets and new ones as the SiRF III set and the MTK set. My old SiRF star II GPS goes completely blind as soon as I'm behind my living room window (there's some metal in it), my MTK-based GPS works fine anywhere in the house (well I didn't try the cellar..), it sees and locks on to 6-10 satellites which isn't much worse than outdoors. The old GPS was a unit where you had to be well aware of its limitations, the new one is an almost use-anywhere device.

It's almost like these magical chipsets are able to overcome the inherent limitations in the GPS system. (I also guess that newer satellites have slightly higher power output than the old ones though, however I have not verified this.)

For the other stuff. PSP, cellphone, iPod etc....

I've now taken my 800 and a bluetooth keyboard on several business trips, and find it more than sufficient for me. I would even say that with the addition of Notecase (I use the Pro version, but the free one is also great), I can write very complex documents. Notecase is a tree-editor: expandable/collapsible nodes on the left pane, and a word processing pane on the right. The only drawback is the absence of spellcheck -- which requires aspell, and I can't find that for the 2008 OS.

Still, I've written several chapters of a book on it.