TechToolsForSchools". A recent post talks about how you might take advantage of the powerful technology that walks into your classroom everyday: the iTouch! Using an inexpensive external mic (the contact info is all available in the post), you can have your students record their voice and work on their accent. The post also mentions a promising app, Audioboo, and a related site, audioboo.fm.
(The mic is listed for $3.50 on the Suntekstore site, but for even less on Amazon.com)