The phone arrived, and I'm recording a few notes on initial experiences, covering mail, the display, the browser, available apps, battery life.
Mail. "Mail for Exchange" worked fine, surprisingly. There are two popular versions of exchange, 2003 and 2007. Last I checked 2007 wasn't supported by Ubuntu (this may have changed but I'm afraid to test it for fear of destroying my inbox or the server itself). There's a 'peak hours' mode that would be better called 'work hours' to control when it should poll for mail. There's a lot of complaints of gMail support on the forums. Need to test that more; in addition to IMAP there's a mobile version of the webapp and the full version works to some degree.
Brightness. Many displays are weak outdoors, due to the physics of LCDs. Essentially, the two options available are to outshine the sun or reflect and filter the incoming sunlight (transflective). Older Nintendo handhelds shipped without any light source, leading some clever people to design LED light that drew power from the gamelink port, or even open the device to mod it with an aftermarket frontlight screen. Wikipedia reports the N900 is a transflective, and it performs admirably in daylight.
Browser. I think I've tried this UI before on some other system images. It's not bad, but the back button is form over function; when I want to go back one click it has to first cook up a scrollable picture history. With Fennec landing on the N900 first, I'd be remiss not to give it a go, if only for the Weave support.
Installable apps. Some quirky stuff going on, like a facebook app installer app and a facebook app. And to the best of my observation, the installer app is larger than the app itself. I suppose at least it's not a free trial. It looks like most of the fun stuff is sitting in satellite repos like extras or garage?
On further inspection, there's a sort of rolling release system in place for extras, loosely modeled on Debian with perhaps clearer names: extras, extras-testing and extras-devel. It looks like most packages reside in -testing, and enabling -testing was similar to Ubuntu's software sources. On the other hand, -devel has giant warning flags in the wiki.
Battery life. My friend Tom insists smartphones are power leeches, so I've been trying to keep it on leash. On the other hand, it seemed to survive a workday yesterday as I fiddled. It charges via microB, which sounds handy until you realize the only microB cable you've got is the one that it came with. We've got countless USB A->B from monitors but no microB. I should break out the Kill-a-watt and powertop, and see what's going on.
Self reported data. I've captured some output from various Linux internal documentation interfaces; I'll post them as comments later.
Just a few random ideas I've had:
Club Carder. Capture and display barcodes for customer loyalty and library cards. Preliminary testing with displaying photographed barcodes suggests that the screen is not transflective, and may defeat laser scanners measuring reflectance. Most of the reviews of the Android app that does this don't attempt retail scan testing, so I may need to borrow a friend's device for comparison. If it does work, integrating with GPS may help recall the correct card for the correct situation.
FlashTorch. Apparently some LED flashes can be driven for longer. Just finished a longish debate on the merits on #maemo, wherein it was determined that the light can be driven in flash mode safely for .5s, and longer at 50mA (less bright but supposedly not bad).
GCStar scanner. Barcode scanner integrated with GCStar or some other personal inventory app. There's already a barcode scanner work in progress, probably just need to concoct a plugin to direct the data.
Cellwriter. Should be possible to port it, the main problem is whether it's actually faster, and whether one can override the onscreen keyboard with it. It occurs to me that you could preload it with Graffiti or Graffiti 2, but I doubt they're fast enough. In my experience, cursive is the way to go for speed. There's certainly spare CPU to process it, but processing cursive requires another error prone step we don't have yet.