I've asked their sales dept.  Meanwhile, here are some others, but I would
really like to hear from someone who knows something about them:

http://www.autotap.com/autotap_windows_products.html  $200
http://www.obddiagnostics.com/  $38 to $99
Alex Peper's CarCode at http://www.obd-2.com

there is a bunch of tools talked about here
http://www.akmcables.com/obdii.htm

http://www.scantool.net/products/elmscan_iso.htm for $80 (this SHOULD be the
right one for Porsche)

there's a PCA article here
http://lpr.pca.org/events/2003/062103-TechSession3/article.htm but it
doesn't mention specific tools

codes are listed here http://www.troublecodes.net/OBD2/

http://www.troublecodes.net/articles/equus/Equuis_OBD_II_code_reader.shtml -
there were a bunch of these on E-bay for $107

There's another list of scan tools here
http://www.troublecodes.net/technical/scaninfo.shtml

so many choices, so little data.....