Something like that.
Multi-signature is much more secure and it is being implemented in several services, Bitstamp and Bit-X are two exchanges already using multi-signature to protect their coins.
If in case one member's account is hacked, then it's a good method but doing this for every transaction is so time consuming and especially when it involves more than 2 people's approval.
It should only be implemented for transactions of 1 BTC and above and not for small transactions.