Smule’s Sonic Vox allows voice transfer in real time on the iPhone.
It’s available for US$0.99 at the Apple App Store
(http://phobos.apple.com/WebObjects/MZStore.woa/wa/viewSoftware?id=293840908&mt=8).
Sonic Vox shifts and contorts your voice while you’re talking,
turning the iPhone into a “magical microphone” of sorts. You can
alter your voice with a swipe of your finger.