[tlrobinson]

IMHO this is the least of Bitcoin's problems. My grandmother doesn't understand the internals of the internet, just like she won't understand the internals of Bitcoin.

Additionally, with BIP-16 (P2SH) and BIP-70 (payment protocol) it is up to the recipient to provide the spend script. Presumably my wallet won't generate a script it doesn't understand. If the wallet doesn't track the required information, whether that's your private key or something more complex, of course you're going to have problems.