I'm a coffee shop programmer as well. Not always, but whenever I want to avoid the potential distractions in my apartment (tv, xbox, bed) I take my laptop and work from a coffee shop for the day. It's also a nice change of scenery.
The freedom to be able to work from anywhere is one of the greatest things about this arrangement. Sometimes I travel to visit friends and family, and that doesn't stop me from doing my work because all I need is my laptop.
How does the coffee shop feel about having people work at their tables all day? I have considered doing this, but I can't quite figure out the etiquette.
If it's not crowded I doubt they care how long you stay. On a weekday during business hours excluding lunch you're fine.
Trying to do high concentration work in a coffee shop would be impossible for me, personally. I don't understand how one could do development. The places I go the general idea is that people are interruptible and open to some conversation and maybe a date.
I have used hotel lobbies. Find a spot to sit and hack the guest wireless for access. The decor and furniture at a nice hotel can be enjoyable. Sometimes you can find an open conference room.
The public library is an obvious option, but they tend to close too early.
Another option is to sneak into local college libraries, or even unused campus classrooms with wireless access.
The freedom to be able to work from anywhere is one of the greatest things about this arrangement. Sometimes I travel to visit friends and family, and that doesn't stop me from doing my work because all I need is my laptop.