I think it’d be cool to see how native cultures would react to seeing a ventriloquist (or anyone else who can throw his voice) for the first time. I imagine he’d be worshiped, or, at the very least, slaughtered for practicing witchcraft. But before that happened, he could play some really cool pranks on people.
In general, throwing one’s voice could be a very handy ability. There are so many choices that I can’t think of any specific applications off the top of my head, but I’m sure I’d use it daily. Oh, I know – just imagine if Chuck Norris could make it sound like someone was creeping up behind his enemy, and then once his enemy’s back was turned, he could leap out and roundhouse kick the crap outta him.