There are awesome technologies today that make it easy to act as a team without being seated close to each other.
IRC, Jabber or similar chat-type software makes it really easy to keep everyone in the team aware of each other, what they're doing, and feeling free to discuss issues immediately. I use IRC with freenode's groups often and it's like having one big group of developers at hand, acting like a giant collective brain. Apple's got a nice chat client build into Mac OS that also supports video conferencing, especially effective with their laptops.
Imagine how it would be if the company had their own internal chat server, with groups for departments, projects, and work-related interest groups. A developer could ask a question where it would be seen across the company, so another developer anywhere else could see it and answer. The office walls disappear, communication skyrockets and best-practices and code sharing can happen all on their own without someone wielding a big stick.
One of our load-test engineers works remotely about 1/3 of the year, sometimes from his home which is about 30 miles from our office, other times from out of state. He is as effective in the office as he is outside it because he keeps his chat software running, and calls in for our conference calls.
My coworkers on my team sit down the hall so I can't see or hear them. I don't know when they are in their cubes so I send them a chat message, and they respond as soon as possible. I do team programming with one of our engineers at another site. The same thing occurs; We ping each other regularly with questions and/or inane thoughts, and if we need to pick up the pace we'll share a screen and get on the phone. I can't tell if he's in the office or at home, and it doesn't matter. We work the same either way.
Our QA department is split between two different cities in different states, our engineers are spread across our city at about four different locations, but it's difficult to tell because we use our phones and chat regularly. We're all working remotely from each other in reality, so what's the difference? The difference is the corporate mindset.
There are a lot of big advantages to working remotely, and mostly it takes a change in mindset for the employer to try and find out that employees respond positively to it.