How Woz Gets Multitasking On His iPhone

Ever the genius engineer, Woz has figured out a simple and elegant way to run two iPhone apps simultaneously (otherwise known as multitasking).
He has two iPhones.
Having two iPhones also doubles his battery life.
"By the way, I solved the problem of battery life and [the lack of:] multitasking on the iPhone," Woz told Dan Lyons of [...:]