Any day of the year is Mighty N900 day for me. My main use (next to standard phone use) is Emacs.

Emacs is not just a fancy editor. My browsing is done from Emacs and it can do a lot more - ERC, task list creation, flashcards, calendar, brainstorming, reading, gaming. Haven't tried to set up my mail with emacs yet, but that it is on my todo list (my todo list created in Emacs of course and so much more.. )
Text on the N900 is very easy to read in bright light (very sunny the last few days)
I own four fully working N900's and not planning to change to another phone any time soon because imho there is still no better alternative.

That was the good part - and now the bad

My N900 was hanging during booting a few days ago so I reflashed it. I have done that before and have a laptop with all relevant files and instructions set up so it took me not more than 30 minutes to have everything re-installed (incl. CSSU / repo's and of course Emacs including .emacs )

Then I imported the contacts from my SIM card and realized that new contacts were not automatically synced with my SIM card and there doesn't seem to be a method to do that at all. Googled a bit and I have read some posts from 2010 that it wasn't implemented by Nokia. Is that still the case?