2 USB into 1 mini USB charger cable?

[joeblow789]

Anybody tried charging their phone with one of these dual USB-A to one mini USB-B Y cables? They typically come with external 2.5" drive enclosures to provide enough power for the drive. It could be cool for a fast full 1 amp charge via USB when no better charging option is handy, and certainly better than the majority of crapola mis-labled under-powered chargers out there. I just can't afford to be the guinea pig if such a cable uses proprietary pinouts and will fry the phone.