What's Your Problem? Figure out what's bugging your classmates and you just might discover a business idea.

Derek Johnson was having lunch with a friend at the University of Houston when he had an "aha!" moment: The friend, a communications director for a sorority, was having a hard time messaging her chapter about important announcements, meetings and dues. Facebook, e-mail and message boards weren't working, so she asked Johnson for ideas. He thought of mass text messaging.

After doing a little research online, Johnson was surprised to find that there weren't any mass texting services for the average consumer. When a friend in a fraternity agreed that he could use such a service, Johnson decided he had a real business opportunity on his hands.

Within months, he launched a website for his new company, Tatango, to sell group text messaging. Now, just two years later, Tatango offers subscription plans starting at $19 a month that allow groups to send text messages to all of their members at one time--whether they are 10 or 10,000--from any computer or phone. The plans also include keywords that make it easy for users to join a group just by texting a certain word.