I think email and forums. Email works great between 2 people and forums are a bit better for larger teams up to maybe 5 people to converse with each other directly. Once you go larger than that you need to break up into groups.
If you use IM for 2 people you usually end up talking about non-sense although sometimes it's useful for "bonding" purposes. I've found oral communication in person or over the phone to be one of the worst ways to communicate and in general just go around in circles. Without the proper amount of time to formulate clear thoughts a conversation about something as deep as game development can be counter-productive unless you're just having some fun.
Email and forums are great because it gets rid of the quick back and forth aspects of a conversation which often lead to tangents caused by people saying something they didn't think through enough. That's my view as far as productivity goes.
If you use IM for 2 people you usually end up talking about non-sense although sometimes it's useful for "bonding" purposes. I've found oral communication in person or over the phone to be one of the worst ways to communicate and in general just go around in circles. Without the proper amount of time to formulate clear thoughts a conversation about something as deep as game development can be counter-productive unless you're just having some fun.
Email and forums are great because it gets rid of the quick back and forth aspects of a conversation which often lead to tangents caused by people saying something they didn't think through enough. That's my view as far as productivity goes.