Leo says that really, the easiest part is the idea. The next thing to do is create a prototype with a local designer to create it. Then, he'll have to find a manufacturer in China to make a production run. He'll then have to try and get a vendor. All that can be difficult and costly.
There are some ways to make it happen though. He could raise money to actually create the product using Kickstarter, a site where people online who are interested in this idea can donate money. Check out the Pebble Watch campaign. They raised $10 million in 30 days. Another option is Indie GoGo.