We'll be in France for a couple of weeks next month, and paying for the house we're renting has involved three trips to the bank and will cost $35 (plus whatever costs are hidden in the exchange rate).
Granted, a couple of those trips to the bank wouldn't have been necessary if we'd gotten everything exactly right the first time. But still... I found myself thinking "paying for this using bitcoins would be SO much easier and less expensive."
Maybe paying for vacation rentals in other countries will be one of the "killer applications" for bitcoin; I bet vacation property owners are the kind of small entrepreneur that might like to cut out the credit card or bank middle-men.