tl;dr Hacker houses are awesome.
When I was looking for a place to stay in the Silicon Valley, I had met this weird place, $50 a night, in dorms, not much fun... After a quick discussion, someone convinced me that it was worth looking at.
The Startup Embassy is what is called a hacker house. A place where people with a tech/entrepreneurial interest can stay while they are in the Valley.
Aside the general convenience provided by the place, I was really astonished by the dynamics here, take a random people in the room, talk to him, he is probably an expert in his domain. Aside the exchanges with different cultures that I usually enjoy very much. The idea just works so well.
Find a way to make rent cheap (the dorm rooms), take people with a common interest and a will to know more people in the area, do a bit of screening (freeriders suck), put those people in the same place. Just wait.
You are done, you have built some impressivestuff to connect people.
This concept was completely new to me ; even though it leaves me very enthusiastic I don't know if places like Paris, or Luxembourg could success in building similar structures. They simply do not drive enough traffic.