It depends what you want to do with the devices... if you want a good internet/web surfing experience, get the N800 as the extra pixels make a HUGE difference. Trust me on this - my VGA iPaq HX4700 now sits in a drawer once I came to the conclusion that surfing on a 640x480 screen is not enjoyable.

If you want to develop software, all of the N800 dev tools are free to download whereas on the Windows Platform you'll probably need Visual Studio .net or some other non-free dev environment. Python is well supported with bindings for the GUI - I can't honestly say how difficult it is to write GUI apps for the N800 as I've never attempted it, but there is a fair amount of documentation available in the Maemo Wiki (http://maemo.org/maemowiki/). You can chat directly with Nokia and community developers on irc (#maemo) or post in the developer newsgroup gmane.comp.handhelds.maemo.devel.

Printing from the N800 is an issue right now - it's not really possible. Not sure if that will ever change.

The N800 RSS news reader is just about usable, but it does have some quite serious bugs that have led to Nokia announcing in Bugzilla that it will be easier to rewrite it than try to fix the bugs. Hopefully a new version will appear sooner rather than later.

US maps should be available for the Nokia navigation app. There is also Maemo Mapper!

Software support is growing for the N800, however it's undeniable that the Windows Mobile platform enjoys more applications.

If you want a solid PDA get the Fujitsu. If you want a device to surf the web, watch movies, listen to mp3s and to hack/develop on then get the N800!