Poliplus's packages work fine on the C3K. Just make sure you load Jeode and everything is fine:
1. Elemental (periodic table)
2. Formula 1 (cool formula/expression solver)
3. Mona (small circuit electrical design pkg, nice graphics)
4. Lisa (Feedback control designer/analyzer - really quite nice)
I installed Calculon which actually allows you to include notes in the calcs and export the worksheet. Surprisingly fast and lots of features. I find this one amazing.
I also have Textmaker and in case you haven't noticed, it has excellent calculation capability built in. You can create variables and use them in strings of equations. That feature alone made it worth the money (I bought the Zaurus, Linux and Win versions).
Now does anyone have a binary of Maxima available for us non-programmers? I used it on a WinCE device a while back (yech) and its much like Derive for Dos.
Is it possible to port Octave onto a Zaurus???