Search and replace across all posts?

Is there a function where I can search and replace across all posts? Here’s the deal.

I have a podcast and WordPress acts as my podcast feed. I’m hosting all the podcasts on the same server as my site, but it’s been suggested to me that it would be more economical to use a special host for podcasts, where they don’t charge for bandwidth. If I do that, though, presumably the domain name would be different. So I’d like to be able to change the domain name in all my links to podcast files, without laboriously changing it post by post. Is this doable?