I went to the fabrics section of Hobby Lobby last night and picked up a quarter-yard of that plastic tablecloth cover stuff (for only $0.45!) I am impressed with how well it seems to work as a screen protector for the Axim.
I didn't really put any effort into getting rid of bubbles, but even still you can't really see the protector when using the Axim. Writing on it seems fine to me. (I have never used any other screen protector.) I think that it even offers a bit of anti-glare compared to the bare Axim screen! (And, now, I can really test out the handwriting recognition with abandon as compared to using the bare screen and being afraid of stratching up the surface.

)
The store had two thicknesses of the plastic sheeting available. The exact thickness wasn't mentioned anywhere, so I just chose the thinner of the two based on a judgement call.
I'll see how this plastic stuff from the fabric store compares to the Clarivue screen protectors when they arrive in a few days. (The only potential downside of the table cloth protector sheeting I can see is if it contained some sort of chemical that could damage the Axim screen over the long term (like baseball cards can be hurt by cheap PVC sleeves over time). Not sure if this is a real issue though.) Right now this stuff seems to be a really cheap and nice screen protector.