My hat is off to Winda Benedetti who has written the definitive article on free coffeeshop Wi-Fi for the Seattle Post-Intelligencer: This lengthy, funny, accurate article on the increasing number of coffeeshops who offer free Wi-Fi as part of their basic business model takes the cake--the coffee cake. It's the best piece written on the subject. (Disclaimer: I write regularly for a competing Seattle newspaper, and have written about coffeeshop Wi-Fi, too, so I'm crying espresso tears as I praise this piece.)
Benedetti extracts all the different facets to the free-versus-fee battle in this realm, including the expectations of the shop owners, the kind of traffic they see (more anecdotal than dollars-and-cents), and some of their righteous anger against competitors who have the temerity to charge for a connection.
There are some nifty subsections about the etiquette that coffeeshops hope their customers engage in--like buying stuff if they use the network--and whether paying for service buys you more reliability than using free networks.
The article ends with a long list of coffeeshops in the Seattle area with free Wi-Fi. I now have several within a two-mile radius of my office--two are within one block, even.