A good toDo list which can be configured for both on-line and off-line working is GTD TiddlyWiki ( http://nathanbowers.com/gtdtw/ ). I used it for quite a while and I was pretty happy with it. I still haven't tried it on the tablet tho.

Other solution is VIM and textfiles. Works well, but it does not look particularly nice.

For text formatting, LaTeX is the way to go and it's not too hard once you get the basics. Is there a LaTeX version for the tablet?

Cheers,
-Igs