I've put a long "Introduction to Mars ISRU" post on my forum at http://www.ibiblio.org/mscorbit/mscforu ... opic=897.0 for anyone who's interested.
One thing that you may have noticed is that pressurized hydrogen is very poor in some performance driven applications. In the case of a compressed hydrogen powered car, the tank is 98% dry tank and 2% hydrogen by mass at 10,000psi (www.dynetek.com), making it rather lame for that particular application.
If any of you are interested in liquifying hydrogen, I know how to start. I'm pretty sure there would be some government paperwork type stuff, and cryocoolers are thousands of dollars (a few are small enough to run on household power) and do-it-yourself maintenance for most problems.
It would not be for the faint of heart, as a pretty big investment. It is also characteristically dangerous (i.e.: you stand an excellent chance of blowing your house up if you are not careful.)