Notecase http://notecase.sourceforge.net/ doesn't appear to support text files, it looks like it shoves all notes into one big (binary) file which I think was what Dormant by txt files.

I too am a big plain text file user for the exact same reasons, they work everywhere :-) I've a Pocket PC and use Tombo http://tombo.sourceforge.jp/En/ (windows ONLY) which uses plain text files also supports encrypted notes. I ended up writing a (pure) Python library http://code.google.com/p/pytombo/ to read/write the encrypted notes so I can deal with them under Linux.

When I get a N810 I plan on writing an interface for it. Right now I have a web based "grep" tool written in Python that should in theory work with Pymaemo (if BaseHTTPServer is installed as this is not part of Pymaemo yet).

One tip for plain text users is to use some sort of wiki-like markup language. I'm a big fan of Markdown (which is what the maemo wiki uses) - this is handy for making "pretty" documents if you need to print something out.

Chris