I use Skype. It is free and it is easy. You can have up to 5 people at a time all chatting together. The advantage is that it is off XMarks (and off all other programmes). This means that someone can point out a thread on XMarks (or elsewhere), you can read it and post a reply while still chatting to your caller. I have answered emails, posted replies on XMarks and held a conversation on Facebook at the same time as I have been chatting to Alex in Scotland!

You can switch the camera off, if you happen to look less than your best and you can switch yourself off to show that you are away or unavailable.

Oh, did I mention that it is free?

Regards

Chas