Net Access on an American Road Trip?

slim asks: "I'm planning a month-long road holiday in August, driving from Chicago to Los Angeles, where possible following old Route 66, rather than the Interstate. I'm not quite dependent on Net access, but it certainly would be nice to be able to use mail, check Slashdot, maintain an Everything daylog, upload pictures from a digital camera to my Web site, etc., along the way. I'm British, and I've already found out that my GSM phone won't work in most of the USA, so fancy-schmancy GSM modem access will do no good unless I buy a phone locally. So what's a Brit to do? What ISPs have a local number in every state? Will they accept a month-long subscription from someone with no U.S. address? Do most hotels have a standard phone socket I can use? Are cybercafes common enough to make do with?"