Dulce de Leche

Put cans of sweetened condensed milk into pot
cover with water
Boil for 2-3 hours, keeping covered with water at all times

NOTES:

First run was a 3 hour open boil.  Let the cans sit in hot bath while pot cooled
off burner.  A nice, soft-set, gummy carmel.  Color was medium I guess.

Read somewhere that pressure cooker for 30-45 minutes works, but no details in
a recipe.  Experiments below:

#2
Second batch was in pressure cooker on high (15lb).  30 minutes once pressure 
was reached.  Relieved pressure to low (8lb).  Moved off of heat and let cool
under pressure.  Overcooked.  Nice, to eat, but still not great.  Too dark.
Possible that the pressure was too much, or cook time was too long.
Not as sweet, since sugars and milk are changed - too easy to eat like pudding.

#3
Put 4 cans in small pressure cooker with water 1/2 way up the cans.
High pressure setting.  Set pot on high heat until pressure is reached.  Cook
15 minutes on high pressure.
Remove pot from heat, rest for 15 minutes.
Dump out hot water, rinse and cool down pot and cans.  Fill with water and
let cool.
RESULT:  Nice outcome.  Almost pourable, with a semi runny center.  Little under
carmelized.
RECOMMEND:  Try 20 minutes under pressure.  Could also consider not giving a tap
water bath at end.

#4
Put 4 cans in small pressure cooker with water 1/2 way up the cans.
High pressure.  20 minutes after steam venting.
Remove from heat.  Rest 20 minutes
Dump hot water, fill pot with tapwater and allow cans to cool.
Result:  Very nice, smooth, after mixing it is pourable at room temp.  
More carmel color than the 15 minute batch previous.
Good for a spreadable Dulce De Leche.