My un-conference talk at Stanford from half a year ago has most of the technical details mentioned and in links. Consider Rosetta Stone, one of the few companies that went public this year, and is doing very well in the down economy. People can get instructional material for free on the web very similar to almost all of what Rosetta Stone sells for more than $150 per unit, except for the automatic pronunciation feedback. So let's offer English pronunciation feedback for free on the web paid for by ads. Try the incomplete demo.
I need to finish the user interface, content development system, put up about 5,000 words of content including Aesop's fables, "choose your own adventure"-style stories, ERIC texts for advanced readers, and license this patent from the British government spin-off that ended up with it. Then put it up on the web as a free ad-sponsored service. Content development involves (1) coding the phonemes and part of speech of each word, as you can see if you try to add another phrase to the demo; (2) getting about 10-15 men and women from Craigslist to record each phrase; (3) a quality-control step where listeners score the pronunciation as being suitable for an exemplar.