Stirling Cycle Cryocooler - Applications?

[Photon939]

A while back an impulse purchase on ebay netted me an old piece of communications gear with a neat toy inside: a stirling cycle cryocooler, I believe it is this model seen here: http://www.suptech.com/sapphire_cryocooler_n.php which would put it at a cooling capacity of 4-5 watts at 77K

I have already used it in a crude setup to liquify air for messing around with liquid nitrogen type experiments, but was wondering if it could have some more interesting applications in the area of electronics. The original application was cooling an RF LNA for cell phone towers or something.

I am also looking to see if anyone knows of a cheap source of gas separation membranes.

[HAL-42b]

You could cool an image sensor for some nifty IR work.

[LaserSteve]

Cool a 635 nm red laser diode down to get an orange or yellow wavelength. Been done, but orange and yellow lasers are rare as hen's teeth.. Or a really low noise RF preamp...

Steve