Not too hard to imagine the porn industry producing the first apps built on this mechanism.

And of course basically any service that is billed per minute via phone today, x-rated or otherwise, would be an ideal fit.  Technical support, legal advice, astrological readings, etc.  It enables all those industries to ditch the phone carriers as the billing mechanism and move to Internet-only delivery and payment.  I'd be curious to know what percentages the phone companies skim off the top on their per-minute numbers, if it's a large amount, then this technology becomes a compelling alternative and some bright enterpreneur could probably get funded and build a business disrupting that market.