In personal computer lore, it was spreadsheets (VisiCalc on the Apple II and Lotus 1-2-3 on the IBM PC) that established the early desktop computers as an indispensable business tool. Desktop publishing helped the Macintosh get a foothold with professionals and Netscape's browser made the Internet accessible to millions of users for the first time.

The smartphone industry has had its share of hits already, including the phenomenal success of Research in Motion's (RIM) BlackBerry line for keeping business users securely connected to corporate e-mail and, more recently, the iPhone -- with its touchscreen interface and highly regarded mobile Web experience.

But smartphones, representing about 15 percent of the overall phone market by industry estimates, are a high-end niche. What kind of must-have application will it take to expand the market?

One hot area of discussion here this week at the Mobile Content & Marketing Expo in San Jose, CA is location-based services -- the idea that your mobile device will provide content, services and advertising based on your geographic location.

Get the full story here at InternetNews.com.