I finally caved and clicked on one of those annoying ads on Technorati featuring talking avatars and was led to SitePal.
So, are you looking for a way to make your web site/blog more fun/creepy? Like....adding an animated speaking character?!
SitePal is the place for you. You can select and customise the character of your choice (think Yahoo! Avatar but with more movement and voice). Basic features include following the cursor (try it out in the demo version) and advanced features include text-to-speech conversion etc.
Unfortunately, it's not free and costs quite a bundle. For a tiny flash animation that chats up your visitors, it's not all that worth it.