I think this is a great idea and I will support including it in the official client.
Apologies if I posted this already - why can't we just add a check digit instead of changing the account number to alphabetti-spaghetti, not perfect but i would catch the majority of errors.
http://en.wikipedia.org/wiki/Luhn_algorithmcause if you look at two strings: DatS7 and opKrN you instantly see the difference, the lesser the alphabet, the less difference is visible on two words over that alphabet...