Try Out This Walkie Talkie
Here's something that I am trying out that I got from Clarence and Anne's blogs. You use it just like a walkie talkie. If you have a microphone, just click on the icon to talk. If I'm at my computer, I'll answer.
Update: Here are some things that I have learned about using this tool over the past 24 hours.
If it isn't working, you can try refreshing your page. That has solved the difficulties so far. (You also need to hold down the mouse button while you talk--just like a walkie-talkie.)
The number in the lower right-hand corner of the yackpack icon indicates how many people are on the page and could theoretically be in on the conversation. I had a three-way conversation this afternoon.
If you use the yackpack and someone (anyone!) has the webpage open, they will hear what you say. Take care!
Update 2 - I've moved the Yackpack to the top of the page.