@mammoth: a simple google search would lead you to http://community.phonegap.com/nitobi/topics/phonegap_build_ios_ad_hoc?from_gsfn=true
Besides that, I have some news:
-The recent release of the HTML5-oriented MobiUs browser (advertised as a "web app browser") for iOS made me full of hope that it would work at least as good as Firefox for Android with C2 games - that is, support sound, even if not perfectly - but still no luck; didn't try my mp3 workaround there, as I doubt it would change anything...
-It will be quite difficult to use Fennec as a wrapper to make a sound-enabled native Android app from a C2 project, as there is no xulrunner (Mozilla's thing to enable such things easily) available for Android (yet).
So for now, a web-app requiring the user to install Firefox is the only realistic option for providing sound to Android users.
Let's hope that the current situation will improve soon!