Barnes & Noble bookstores and AT&T are now offering free wireless internet access to everyone. You can use this storefinder to see which ones have free Wi-Fi. Seems like they are now promoting their own e-Books as well through the service. Via Lifehacker.
You can still get 2 hours of free Wi-Fi every day from Starbucks if you register a gift card and use it once a month. Sometimes you just need a change of scenery to get the inspiration going again.