E-mail device. Web surfer. Digital calendar. Address book. Music player. Camera. GPS navigator. Game console. By its very definition, a smart phone these days can do a heck of a lot right out of the box. But you’re not realizing your device’s full potential if you don’t take advantage of the fact that your pocket computer can run dozens (in some cases, thousands) of applications. And many of the best apps are free.

The programs that made our short list can help you do nearly everything, from performing Google searches with your voice to keeping tabs on business travel plans and finances on the go. And because smart phones are just as much about play as they are about work, we’ve also included some fun entertainment apps and games for killing time between meetings or while on a long flight. (That’s what airplane mode is for, after all.)

Why are smart phone apps getting so much attention now? Because they’re much easier to acquire than in years’ past. Apple has been leading the way with its delightfully simple App Store, which lets you download programs over the air straight to the iPhone (or from within iTunes on the desktop) and look at star ratings from other users. And Google’s Android Market for the T-Mobile G1 (and subsequent Android devices) has followed suit with a similar look and feel.

 RIM, which promises to launch its BlackBerry Application Center in March, and Microsoft’s Windows Mobile OS (which hasn’t even set a timetable for a digital storefront) are playing catch-up, but finding the apps you want for these operating systems is far from difficult. In general, it’s easiest to visit the mobile Web site of a given application and install it directly.

Plenty of pay-for smart phone applications are worth their cost, too. You can see our top five premium picks for all of the above platforms below too.

Apps For Free	Apps Worth Buying
iPhone Apps  Click here » Android Apps  Click here » BlackBerry Apps  Click here » Windows Mobile Apps  Click here »	iPhone Apps  Click here » BlackBerry Apps  Click here »  Windows Mobile Apps  Click here »