http://www.wired.com/news/technology/0,70179-0.html?tw=rss.technology
And try Alistair Cockburn's classic article on the effectiveness of various forms of communication: http://alistair.cockburn.us/crystal/articles/cpanfocisd/characterizingpeopleasnonlinear.html
We're a little satellite office and we suffer from some occasional communication gaffe's related to email misunderstandings. Body language doesn't come across over email and it's very easy to offend somebody in an email. Nothing beats face-to-face communication, but I think you're better off picking up a phone to discuss anything that could be contentious rather than relying on email.
We struggled a little bit when our one and only tester was at a different office. Email is a bad enough, but depending on a bug tracking tool for developer-tester communication is borderline insane. The clincher for me was the time I stumbled over some hidden tab in the bug tracking website and found a really whiny, passive-agressive comment about the developers not giving the tester enough information. No phone call with questions or even an IM, just a pissy note hidden away in the bug tool. Grrrr.
One of my former employer's had the bright idea to outsource a lot of coding overseas, but keep all of the testing and analysis in Austin. Let's see, developers and testers spread out over about 12 hours time zone difference on two continents and only talking through documents and email. That sounds like a great recipe for total failure. When I piped up and said "this isn't going to work" the manager in charge of the offshoring just looked at me funny.