If I'm selling an item in person for bitcoin instead of cash, what do I need to do to confirm that the transaction is completed and secure? I don't want to walk away after handing over my stuff until I'm sure that the bitcoin is safely in my wallet.

It looks like localbitcoins.com requires 3 confirmations before a transaction shows up in their online wallet. Bitcoin protocol requires that 6 blocks confirm the transaction before changing from "unconfirmed".

Is there anything else I should be aware of when doing a bitcoin transaction in person?