First off, PalmOrb works by pretending to be (or emulating) a real LCD; a Matrix Orbital LK204-25 LCD. So you can use existing software that expects a Matrix Orbital display! Here are a few LCD driving programs:
Linux: LCDproc - free. [LCDproc v0.4.5 has a number of minor bugs; see FAQ.]
Linux: LCD4Linux - free.
Windows: LCD smartie - free. v5.4 is the latest, beta versions are available.
Windows: LCDC - shareware but it's very good.
You will also need to download PalmOrb from here: http://sourceforge.net/projects/palmorb/
You will also need to make sure that your palm can sinc with your pc as this is needed in the intallation process.