Free condoms are useless if people can't find them. This problem was brought to the attention of 33-year-old French entrepreneur Margane Danielou, when one night not long ago, a friend of hers met a guy. Being responsible young adults, they knew they'd soon need condoms. 

However, the moment of need came after 2 a.m., when metro stations and convenience stores were closed. In after-hours situations such as these, Parisians can try to hunt down government-established condom dispensers. Unfortunately for Danielou's pal, the only one she found was broken—as was the spell of the moment.

Determined to find a solution to this prevention problem, Danielou created iCondom, an iPhone application (launched in October 2010) that locates condom vendors and dispensers throughout Paris and Marseilles. To commemorate World AIDS Day 2010, iCondom was released in the United States for free for a 48-hour period. In a single day, the application was downloaded more than 9,000 times. It's now available in the iTunes Store for 99 cents.

The application uses crowd sourcing, geolocation and Google Maps to pinpoint the closest available free condom—whether it's in a barbershop, family planning center, hospital or church. (The U.S. version does not locate stores that sell condoms.)

Many user comments in the iTunes Store found the app to be “not functional” or “LOL,” but Danielou remains confident. “The problem is that for now there are only four cities with 50 to 200 locations registered,” Danielou says. “The idea is for iCondom locations to grow with the users.”