Just be careful about doing this without the nitrogen separation membrane. Because liquid nitrogen boils before the liquid oxygen (or alternately it's easier to condense liquid oxygen), you will end up with a container full of liquid oxygen.

Now, while that can be fun to play with, it's pretty dangerous if you are not expecting it.

"Information regarding these membrane units is easy to find on the internet, but good luck buying one! They are nearly all produced for huge industrial installations, and those manufacturers will not even return phone calls from interested hobbyists."

I look forward to seeing the equivalent of sparkfun for homebrew cryogenics.

Interesting, though, for DIY, I was expecting him to do it the way Linde did, back in 1894, that being:

  Compress some dry air.
  This will heat it up, so cool it down.
  Return it to atmospheric pressure.

While expanding, it, of course, gets even colder still, and condenses. Liquid nitrogen is old tech, older than you might think.

Very cool. I love seeing people cobble together high tech/complex equipment in their garage.

This could come in handy for the insane overclocking crowd and the arguably insaner DIYBio crowd. The advantages of being able to store cell/other cultures in LN should not be underestimated. Countdown to Homeland Security/FBI overreaction in 3, 2...

What would you do with the liquid Nitrogen you generate? What is the hello world app of cryogenics?

safety tip for storage is a pressure relief valve on the tank and beware of suffocation risks during/if a LN2 spill, gas volume of N2 may displace enough air for asphyxiation to occur - good labs have O2 sensors in their LN2 storage areas. never transport a thermos of LN2 in your car or a lift etc

seems like he got very lucky/spent a very long time searching ebay to find the right parts to make this work. I don't think you would easily be able to replicate this.