Open Thread: How Do You Chat?

The addition of Gmail Voice and Video Chat to Google’s list of services brought back to mind a question I’ve been thinking about for a while: have we gone past the saturation point in having different ways to chat with people? Even if you count only real-time ways to talk to people, there are a pile of instant messaging applications, more audio chat options and conference call providers than you can shake a stick at, and video options including Skype, Oovoo, and Gmail – to name a few.
And that’s not to mention just walking down the hall to talk to someone in person, which is not an option for a lot of web workers.

So, given all the choices: which ones do you actually use to communicate with friends, family, clients, and co-workers? And how do you decide? Is it technical superiority, multi-platform availability, installed base, or something else? Do you find different chat tools work better for different tasks or types of conversations? Or are you firmly stuck in a model where realtime chat wastes your time, and you settle for email, or picking up the telephone when you really need to talk to someone?