How disappointing. For a second there I thought someone had designed an iPod case based on the works of H. R. Giger.

I really need to buy a home injection molding machine.

hmm - nothing like having a 300-ton press in your living room. Just so you know, you'll need a cooling system, some serious amperage and space, along with an entire machine and design shop so you can make the molds.

However, that being said, it'd be a whole lot of fun to make stuff that way...

Dude, I'm looking to make things, not manufacture them. There are injection molding machines the size of a large glue gun these days, so space isn't the issue. All I'd need after that is to turn the shed into a mold building workshop, and practice sculpting molds until I'm good enough that people start paying me for custom iPod and cell phone casings...

ahhh - and I worked on the manufacturing side, hence the difference.

But then again, wouldn't it be a bit easier to just mill them down into the proper size and do shaping from there?

And how do these things work? I'm assuming the molds aren't heated/cooled, made of metal, etc. Correct?

You can use metal molds with them, in fact it's highly recommended. But they also can be used with wire-reinforced ceramic molds, and even some plaster ones if you use a lowmelt plastic and minimal pressure (though it's not recommended).

Generally the process is:

- fill the "glue gun" chamber with the desired filler and heat it to spec
- clamp it to the injection hole in the mold
- pressurize chamber to necessary degree with air compressor
- pull trigger

If all goes right, after depressurizing and cracking the mold, you have a custom-made plastic junction box, bottlecap, or whatever your mold was for. Screw up, and, well... let's just say the failure modes are all extremely messy, hazardous, and expensive.