since I wanted to buy a new mp3-player anyway and the price of the N800 dropped to ~230€, im now thinking about buying it instead. I could get a 8GB SD card for another 50€ which would fit my music library.

but I have still some questions regarding the device:
- is it possible to make the native player play ogg? (i know ogg is basically possible using mplayer)
- is it possible to run wesnoth?
- is it possible to run zsnes?
- pidgin?
- is some kind of synronistaion with the desktop possible?

Im running Ubuntu and I can compile stuff myself if its necessary.

check the app library i know i saw pidgin in there. not sure about the rest. maemo.org

Wesnoth is there. So it is pidgin. Both are exactly the same with desktop versions.
I am sure there is maemo-ogg-support package (can't remember the exact name).
In the gaming section there are a few NES emulators, Mame, PS1 (not very playable I suppose).

As far as I know, there's a package that allegedly allows you to play ogg with the native player, however it's never worked for me... or required you to rename your oggs as .mp3 for it to work.

I think someone did a port of Wesnoth.

No, ZSNES is currently impossible as it was originally written in X86 ASM. It is currently being slowly rewritten in C, but it's going to take a LONG time for that to happen. You'd be better off trying SNES9x, however there's no real way that you'll get much of anything that's playable at all.

Pidgin already has a port, yes... however I find that using a Jabber server with the external gateways on the built-in messenger is much better, especially with RTCOMM beta installed.

Some people have managed to do some sort of syncro, most likely using the GPE series of apps.

There are packages for installing Ogg codecs on the N800, but the built-in media player won't recognize Oggs when scanning the filesystem... I never got Ogg Vorbis working on the N800, except with mplayer. I'm currently working on a usable frontend for mplayer (for both, video and audio).

The 770's built-in media player can play Ogg Vorbis just fine after installing the codecs, though.