I've been playing with Oddcast's Sitepal for the past few months.  How do you like me?

Click on my mouth and make sure your sound is turned on.

It was very easy to set this up. The site has an online editor that lets me pick any of a zillion personas (including this custom one), each of which I can control to do different things depending on user input or timing. They make it easy to plug it into my web site too, with pre-populated code for all the major sites like MySpace or Blogger. I can see kids putting this on their blogs as a way to differentiate themselves or liven things up a bit. Of course it comes with a built-in TTS engine so you can make any of the personas say whatever you like.

Personally I'm usually annoyed when I hit a web site or ad that automatically plays audio. What if my boss is around? What if accidentally have my speakers turned up too loud? It's just kind of rude to exploit sound on a site as a way to attract attention. Fortunately, I can turn that on and off and make it responsive to a user click, and I think there are cases where it really would be useful.

Anyway, if you've been wondering what I look like, this cartoony image isn't all that unlike the real me.