So if you and a Firesheep user are in a coffee shop together taking advantage of free wireless and you visit a non-encrypted version of Facebook, the Firesheep user can hop into your account and take a look around.
Given how easy it is for a customer to walk across the mall to your competitor, or price shop your products online, your competitive advantage is largely derived from how well you develop a relationship based on trust.
The euro should spur price convergence not so much because consumers shop across borders, but because greater price transparency encourages wholesalers to take advantage of price discrepancies.
The advantage for passengers if this policy catches on: the ability to shop around for the best price for each leg of a trip -- even on different airlines.