I've worked at Automattic (a distributed company) for more than 5 years. The number one communication tool/method for most teams is IRC. We run our own internal IRC server, that logs everything in every channel. IRC is great for real time chat, when people are around at the same time.
Next most used communication method are internal P2s - http://p2theme.com/ - which is great for async communication. With people all over the world it is important to have a good async communication method.
Another reason both IRC and P2 are so important is that they have URLs for history. Anyone in the company can go back and read through the discussion.
The third communication method is Skype/Google Hangout. Many teams will have a regular (weekly is common) voice or video chat, generally less than an hour.
Next most used communication method are internal P2s - http://p2theme.com/ - which is great for async communication. With people all over the world it is important to have a good async communication method.
Another reason both IRC and P2 are so important is that they have URLs for history. Anyone in the company can go back and read through the discussion.
The third communication method is Skype/Google Hangout. Many teams will have a regular (weekly is common) voice or video chat, generally less than an hour.