I picked this one up from the MSDN Blogsphere (sorry to echo back to MSDN`ers)

 By default, the AJAX Control Toolkit's AutoComplete extender doesn't have a notion of "words" and will try to auto-complete whatever text is currently in the text box, treating what's there as a single "word". One request that has come up a few times was for the ability to auto-complete multiple words individually. According to the comments of that work item, it looks like someone's made a set of proposed changes to do just that! It's great to have such an involved user community!! (Please note: The work item comments suggest those changes don't work in all browsers.)

This is pretty damn cool if you ask me..

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