Just had an 'A HA!' moment..followed by a "WTF are you thinking" moment...
Anyhow..I brewed up a 1 gallon test batch Monday, just to get my feet wet (I did get my feet wet at one point ) before my 5 gallon batch this weekend.
I used my 8qt pressure cooker's 'pot' as my main mashing / boiling vessel since it was a small batch, after words I transferred to a glass gallon bottle / airlock etc.
I just thought to myself, "Self...the pressure cooker has an airtight seal, its opaque and has a small 'hole with a metal tube thingy' exiting the top...I bet you could attach silicone tubing to it, and call it a fermentor".
My WTF moment was caused by the hole being about 1mm in diameter...but man it would be cool to be able to boil, remove from heat, put the lid on immediatly, and have it "sealed" and cooling in an ice bath, and only needing to pitch and put a tube on it once cooled.
Im pretty sure something would go wrong here, but I figured I'd mention it so that others could talk me off this cliff.