First was the mouse. The second was the click wheel. And now, we're going to bring multi-touch to the market. And each of these revolutionary interfaces has made possible a revolutionary product - the Mac, the iPod and now the iPhone.

I'm convinced that about half of what separates the successful entrepreneurs from the non-successful ones is pure perseverance... Unless you have a lot of passion about this, you're not going to survive. You're going to give it up. So you've got to have an idea, or a problem or a wrong that you want to right that you're passionate about otherwise you're not going to have the perseverance to stick it through.

It's rare that you see an artist in his 30s or 40s able to really contribute something amazing. Of course, there are some people who are innately curious, forever little kids in their awe of life, but they're rare.

I think if you do something and it turns out pretty good, then you should go do something else wonderful, not dwell on it for too long. Just figure out what's next.

Things don't have to change the world to be important.

When you're in a start-up, the first ten people will determine whether the company succeeds or not. Each is 10 percent of the company. So why wouldn't you take as much time as necessary to find all the A players? If three were not so great, why would you want a company where 30 percent of your people are not so great? A small company depends on great people much more than a big company does.

To turn really interesting ideas and fledgling technologies into a company that can continue to innovate for years, it requires a lot of disciplines.