really think the bitcoin setup program should address this problem.
either ask the user for a backup location and backup after every personal transaction or some other solution.

at the minute it's left to the user.
which is not really fair if your system goes down.
fatally!!

edit:
come to think of it, it's totally unfair.
this needs to be more secure if you can lose your entire bc account due to just carelessness or bad luck!!
wouldn't get many bankers using a system like that!