Sure, iPhones have been around for a while.

But with the advent of the iPad, explosive sales of Android phones, and an ever-expanding market for mobile apps that work on any Web-enabled phone, there is plenty of fresh territory for programmers, developers, and designers.

One tip: Keep location in mind. Venture capitalists and industry experts alike expect the location-aware economy to grow at the rate social media did.

In the past three years, companies that make location-based apps alone have received $656 million in 67 deals, according to Dow Jones VentureSource. 

By the numbers:

Amount received by companies that make only location-based applications over the past three years and 67 deals: $656 million