How do you plan to make them (un) recoverable?
Armory has (or will have soon) an awesome feature built into the paper backup system that allows an M of N recovery. Fully customize-able.
I plan to print 10 sheets of paper that each have a piece of the puzzle to recover my cold storage wallet. It will require 7 pieces of the original 10 to recover the wallet.
6 of them get distributed to family and friends with instructions to hold onto them until I die.
4 of them are to be in the will itself, this way, the other 6 can never do anything before I actually die (not that I couldn't trust those people).
Seems pretty complicated.
Wouldn't it be easier to create a RAR archive containing the wallet with enough repair/recovery data, and give only part of the data to your family ?