To me, that reads as an assumption that, at some point, you'll have to get an office. But what I want to know is: can you build a virtual Fortune 500 company?
But we also find that the fast paced environment our partnership people work a lot better when they can sit together and bring in people to see them at a fixed office.
We are sub-letting, but we have a headquarters. However, the majority of our people (6 people) work from home. And anyone can telecommute whenever they want.
I think the founders don't work there full time at either, but I'm pretty sure some people do.
Our downside to this was twofold however:
1) We choose our team poorly & it was too big. That isn't to say that these aren't all simply wonderful people, but for making a highly efficient machine- it was a hodge podge of people with various levels of interest, skills, experience and commitment. We crept up to 10-12 people quickly and since it wasn't a formalized business structure at first this seemed ok. We were however all in the same geographic location (Cambridge).
2) We had too many meetings, which people stopped attending and become ineffective. These became a time sink. People would defer conversation to the meetings instead of our internal email list (which for some conversations is the right thing to do), but then these became lengthy 4-5 hour meetings that stopped getting things done. Our coding slowed. Decisions stopped being made, interest was lost slowly.
These are points very specific to our group and I totally agree on holding off on office space until you MUST have it. Keeping costs down and excellent workflow up initially are a must. Just don't try it with 10 people and don't kill people with mandatory meetings. Use IRC or some other tool religiously.
If anything, look into a coworking space like Betahouse (http://betahouse.org) or New Work City.
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).