Use your local library.
During the year we started Matasano our Chicago team spent about 40%-50% of our time working from the Oak Park Public Library, sometimes in meeting rooms we booked, more often at study desks. It was great. The Internet access wasn't amazing but it was totally functional and we could VPN out through it. The desks and working space were if anything better than what we have now (and we really like our office).
There were times I worried that we were being a burden, but the impression I get is that it's the opposite. What's deadly for a local library is for nobody from the community to be using it, for it to have no stakeholders from the tax base of the community. The library staff was always welcoming to us.
Your hip coffee shop on the other hand hates you with a passion it normally reserves for Scott Stapp solo albums. At the coffee shop, you take up space in a business that's driven by turnover. Someone's going to chime in here with a story about a coffee shop that truly loves the startups that park themselves at their tables and order 3 count them 3 cups of coffee in a day, but I've talked to hipster coffee shop people oh-yes-I-have and at least some of you who truly believe you're doing your coffee shop a favor are being tolerated gracefully, not welcomed, like you would be at your local library.
Libraries have an obvious role to grow into as IT hubs for their communities, now that so much of their knowledge-disseminating role has been subsumed by IT. But another related less obvious role is as a hub for local entrepreneurship; thing thing "hackerspaces" are supposed to do, but are (for so many companies) suboptimal at.