Another Google Wave video to see

I had two questions about Waves. One: How can you tell which are the latest edits to a wave. Two: Is it possible to know if any of your contacts are online and in the Wave application? I think I have the answer to my first question (A vertical green bar appears on the left edge of the wave entry), but I don't yet know the answer to the second question.

However, I did find another good video to suggest. It showcases 15 features of a wave, in rapid fire succession. Here it is:

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