I believe Google Voice offers machine transcription of voicemails. Not perfect, but better than nothing!
I agree that this sounds like a business opportunity. Perhaps use Amazon's Mechanical Turk to outsource transcription to humans (who tend to be better at this than machines)?
I agree. Sounds like a great app, but to be useful, I have to pay for it and so do each of my friends (unless you add the email / SMS feature suggested above).
I suggest a fremium pricing model. Perhaps all features are free exept one killer feature, which is an optional in-app purchase. For example - push notifications when one of your friends suggests an activity.
However, this idea eliminates the risk that your uers won't bug each of their friends to install your app.
Also, the right design for the email notification can act as great marketing for your app. You can certainly make a better landing page on your website than your app's product page in the App Store.
I agree that this sounds like a business opportunity. Perhaps use Amazon's Mechanical Turk to outsource transcription to humans (who tend to be better at this than machines)?