BP in New Zealand is adding Wi-Fi to its cafes at gas stations: Once 802.11g products are widely deployed in the market, I think implementations like this one will start to appeal more to the mass market. Ideally people could pull into the gas station and download music or movies to their Wi-Fi-enabled cars. Such entertainment applications will draw additional users.
(Glenn notes that Estonia was the first country in which Wi-Fi was available at gas stations -- apparently, they pioneered a number of interesting combinations of Wi-Fi and other services, but are rarely cited because of their remoteness.)