Automated Service Agents, and SmarterChild
John Mullinax has mentioned SmarterChild a couple of times so I had to do a little Internet exploration.
A couple of years ago, Microsoft purchased a company that provided us with Automated Service Agents (ASA). It's very cool stuff, and the basis of bots (or chatterbots, agents, etc). Basically, you can serve up a automated service agent via a instant messaging application like Live Messenger, or even from your website (I.e alternative launch points as Devon would say). Microsoft hosts the technology behind this, and you just provide the lexicon. This technology also supports dynamic requests - where the response includes HTML and even calls to additional web services - like "where's my order?" would require a call to your custom service, for example your "order inquiry web service".
Another cool thing that came from this is sample agents that you can play with today - like SmarterChild and other agents. SmarterChild is interesting because you can use it so easily. Not that I'd want to use this agent every day, but it does show how easy natural communication can be with a computer. Check it out. You just add a contact using the email address of email@example.com in Live Messenger or Communicator, and you're off to the races.
Customers around the US are adding this type of functionality to their customer service portfolios, so you should check out ASA if your company has or needs a call center, telephone support, web support, customer service, etc.