Here it is January 2010 and I still find my N800 non-replaceable. At this point in my life, I can afford to buy any device I desire, but I hold on to my trusty old N800. I would pay $3000 for an updated N800 that has a direct sun-light readable display, a built in SENSITIVE gps receiver, a high res, low light camera on a swival mount, and Skype with video. And although the cell phone function would be nice, the only way I would use the cell phone is if it were Verizon campatable.

And a battery life of 8 hours or real use.
Only, I'd pay $300 instead of $3000

Though I adore my N800 I did get an N900. Now the N800 is my alarm clock--a Chumby if you will. I move it around the house with me as I get ready for work (radio, podcasts). Even in the room while showering. And I am looking into ways to use it as a secuirty camera (to replace my old iBook that takes photos when motion is detected and emails them to my phone).
It has served me well.

I own both a n800 and a 770, I still carry my 770 with me most of the time, much more than my n800. Even though it cannot run all the softwares out there for ITs, but the hard case and the lighter weight compare to n800 does won my heart. And a lot of time when I pull out my 770 and show it to my friends, I still can impress them with all the functions, eg remote controll my home computer, play snes games, watch cable TV over the internet, listen to the internet radio from oversea, make phone call to the USA when I am oversea, keep my eye on the stock market all day long, etc etc.........a lot more to show off.

I recently downloaded Fring http://www.fring.com/ for my N82 phone. As I understand Fring doesn't have anything to do with Skype company but their (free) software makes Skype video calls from cellphone possible.
So maybe it could be possible to get Skype video calls also to our N800.

It's good to see an N800 thread. Skype is no longer an eBay company, as I understand it. Someone mentioned wanting a GPS with the N800. The external GPS has the advantage that you can move it somewhere to get the best signal (such as near a window) butt still keep the N800 with you.

All those skype users may want to keep Gizmo in mind. I use Gizmo to call the states when i'm in Mexico. There is also video calling (albeit not very good) with Gizmo using the N800. I used it a time or 2 and it can be hit or miss at times.

gizmo is part of google now, iirc...

Tear plus Advoid is terrific for browsing the web.
Kchmviewer is awesome, awesome, awesome since I'm no longer lugging around books like I used to.
Garnet VM I use almost daily with the huge database of apps I have for it.
Xkbd finally works with no repeating keys like it used to. This opens up so many more opportunities of being able to use programs that weren't possible before.
Xbindkeys is easy enough to map new functions for the few hardware keys on the tablet including launching apps with a single press of a button or enabling a right mouse click.
Watching videos does somewhat blow. The best results I've found are watching cartoons like the Simpsons.
Many choices for playing audio files. I don't have all that much music but I've got a huge folder of Kaplan lectures I listen to.
Pidgin rocks especially with qwerty's LED notification.
Dial Central probably saves me around $300 yearly for making phone calls and sending and receiving SMS messages.
For stress relief, I usually enjoy Dosbox (currently playing Castle of Dr. Brain on expert level) and I still enjoy old school Telnet games with ADOM being my favorite.
Of course there's always SCUMM as well.
Shin Megami Tensei 1 and 2, Wonder Project J, Front Mission and Wizardry Trilogy works really great on the little handheld. Kirby's Dream Course works okay.
SCID lets me watch international matches live between two Grandmasters with an analysis engine running in real time which is quite entertaining for me.

I feel like I'm still leaving out about a couple of dozen more things that I haven't mentioned.

Fring hasn't released an update for their maemo client in "ages" and I don't think they ever will.
I think that maemo being an open source project should try to get Empathy going, as of now it provides "voice and video call using SIP, XMPP, Google Talk and MSN".