Oh and Backpacker....
Im going to have to entirely disagree with you on the squwking!
You should ALWAYS chasnge to 7700 in an engine failure... or anyother situation regarding immediate emergency assistance!
This is the only wauy to ensure that whosever radar coverage you are in is immediately alerted to your position!
7700 flashes up and lights up the screen bringing attention straight to you, If it takes away your ident, what does it matter!? there are still going to be services sent to aid you! and accompamying a distress call, its not going to take a genius ATC to put two and two together and think 'Hm, station transmitting distress call must be the same as person squawking 7700!
121.5 - airline pilots continuously monitor it. US + Canadian ATC always monitor and record it!
Cheers,
JV