Last Updated Dec 16, 2008 11:17 AM EST
And a compatible phone. The free Truphone app is available for BlackBerry, iPhone, 2nd-generation iPod Touch, and various Nokia phones. Once installed, it lets you call other Truphone users free of charge. You can also call landlines and mobile phones for significantly lower rates than you'd normally pay.
Calls from the U.S. to an India landline, for instance, cost 10 cents per minute. Calls to the U.S. from other countries run 6 cents per minute for both landlines and mobiles. You can also use Truphone to send text messages for 20 cents apiece.
During a recent trip to the Bahamas, I was able to test-drive Truphone on my iPhone. Instead of paying AT&T $2/minute to call the home office, I paid Truphone 6 cents/minute. This after walking into a Starbucks (they're everywhere down there -- go figure) and using the awesome Easy Wi-Fi applet to get connected in a flash.
Actually, I paid Truphone nothing initially, because the service gives new users a $1 credit. So I got about 16 minutes' worth of free call time. The sound was a bit muffled, but quite good overall. Thus, I can't recommend Truphone highly enough for anyone seeking to save money on international calls.