[greenyoda]

It's entirely possible to have a professional relationship with your co-workers without them being your friends. I get along very well with my co-workers on a professional level (e.g., I'm always there to help if asked), but I socialize with only a handful of them, and very few know anything about my personal life.

[sssilver]

It's certainly possible, but that would make me personally feel very uncomfortable around these people, and I would eventually float towards working in a more tightly coupled team with relationships that transcend work.

That being said, many people actually prefer having that distance. For me I find that distance bothers me, and that may be a cultural thing.