Onstage at the D11 conference in California, Tim Cook responded to a question about Google Glass, noting that wearables are a profound type of technology and that Apple may be working on its own wearable tech. "It's an area that's ripe for exploration," Cook said, "it's ripe for us to get excited about. Lots of companies will play in this space."

Cook said that the iPhone pushed Apple forward fast and that tablets accelerated the company's development — but noted that Apple has room for growth. "I see [wearables] as a very important branch of the tree," Cook said. "I think this group will be very involved in this."

"There's nothing great out there that I've seen."

Cook didn't reveal exactly what kind of wearable tech Apple might be interested in, but said that Nike "did a great job" with the Fuelband, noting that he wears one. "There are lots of gadgets in the space," Cook said. "I would say that the ones that are doing more than one thing, there's nothing great out there that I've seen. Nothing that's going to convince a kid that's never worn glasses or a band or a watch or whatever to wear one."

Apple has been rumored to be working on a curved glass smartwatch, expected to run on iOS. The Verge has been told that a team, led by Jony Ive with some 100 engineers, is working on the project, and that it is expected to be released later this year.

"To convince people that they have to wear something, it has to be incredible."

As for Glass, Cook was (perhaps naturally) less optimistic about Google's prospects. "There are some positives in the product," Cook said. "It's probably likely to appeal to certain markets. The likelihood that it has broad appeal is hard to see." Cook said.

"To convince people that they have to wear something, it has to be incredible," Cook said. "If we asked a room of 20-year olds to stand up if they're wearing a watch, I don't think anyone would stand up."