I found some informations about your problem:

1st
You should run a SW which is working on your Zaurus i.e. qpeGPS [1]. This is freeware which is the whole idea behind Linux. I think you can only sell the card Holux GM270 but not the SW.

2nd
The SW can be downloded [2].

3rd
I found some further informations about your card (Holux GM270) [3]it seems that it is not running out of the box, but if you follow the link you find a nice howto.

Just my 2 cents

Regards

Dave

[1]
http://qpegps.sourceforge.net/index.html

[2]
http://sourceforge.net/project/showfiles.php?group_id=55933&release_id=162987

[3]
http://qpegps.sourceforge.net/assets/gps_units/holux_gm_270.html