I agree with the point that you don't need office space early on. The key is being in constant contact with the other team members. Some developers love to chat

I agree with the point that you don't need office space early on. The key is being in constant contact with the other team members. Some developers love to chat/IM on skype all day long from home. It depends on your team dynamics. But once in a while, you need serious face-to-face brainstorming. That's where your coffee shop probably saves you. No one has designed a tool yet that allows several people to really have a brainstorming session remotely (hint for a future YC startup: if you have a solution to this problem, go for it).