At the time he was selling, Jay-Z was also coming up with rhymes. He normally wrote down his material in a green notebook he carried around with him — but he never took the notebook with him on the streets, he says. "I would run into the corner store, the bodega, and just grab a paper bag or buy juice — anything just to get a paper bag," he says. "And I'd write the words on the paper bag and stuff these ideas in my pocket until I got back. Then I would transfer them into the notebook. As I got further and further away from home and my notebook, I had to memorize these rhymes — longer and longer and longer. ... By the time I got to record my first album, I was 26, I didn't need pen or paper — my memory had been trained just to listen to a song, think of the words, and lay them to tape." Since his first album, he says, he's never written down any of his lyrics. "I've lost plenty of material," he says. "It's not the best way. I wouldn't advise it to anyone. I've lost a couple albums' worth of great material. ... Think about when you can't remember a word and it drives you crazy. So imagine forgetting an entire rhyme. 'What's that? I said I was the greatest something?' "

Apple is reportedly working to bring a number of features to the iPhone and eventually develop wearable, wireless glasses that display content in augmented reality.