Cindy-

>I'm pretty sure you can automate Microsoft MapPoint if that would do the trick - but it's not a web service.

I thought of that, but of course they'd need licenses for it, and if they have a lot of concurrent hits, that could be expensive. But, yeah, it's a great tool.

But, maybe mapquest will be available as a webservice sometime soon, or if it is already someone here will know.