I thought I was looking at a video. Then, I realized I was looking at my AV!
That's a quote from someone who entered Cloud Party accidentally. She hit the page on my blog that has my virtual island embedded in a frame and she was logged in automatically. She only realized it was "her" on the screen when I mentioned her name in chat.
Most of us are spread across multiple shared virtual spaces throughout the day. Just on my phone, I may have different identities represented on Twitter, Facebook and Google+. Although we have a sense of being present within the shared conversational space of the social stream, we don't have a psychological sense of physical presence. Although our profile picture is sitting in thousands of people's screens next to our posts, it doesn't feel like we're there. But when we look up and notice that our avatar has been standing in a virtual world there's a visceral sense of WTF. Very freaky.