IVR Technologies, a software developer specializing in IP services, on Monday rolled out new applications for making affordable long distance calls on Windows Mobile 6-based smartphones

The applications -- Smartphone Calling Card and Callback -- are add-on modules for Talking SIP, IVR's application, media, and billing server. They can be integrated into smartphones running Windows Mobile 6 to facilitate cheaper mobile international long distance rates.

Using the Calling Card app, a call can be made immediately with automatic authentication of the caller. The Callback app can be used to make a request to dial a specific destination; the app rings the user's phone and connects them with the requested number. This gives smartphone users the option to make long distance calls in the same manner and with the same quality as local calls, according to IVR.

"Our core product, Talking SIP, is deployed by next-generation VoIP carriers that provide residential, business, and consumer voice services to both fixed and mobile customers," said Barry Sher, VP of business development at IVR, in an e-mail. The new add-on applications use less expensive next-generation services instead of traditional wireless networks that are too costly for making international calls, he added.

VoIP carriers have started deploying IVR's Smartphone Calling Card and Callback, but the company didn't provide names of the carriers.

Mobile users already have other options for making affordable long distance calls on their mobile phones, and not only on Windows Mobile devices.

Raketu last week introduced a Web-based VoIP calling application for BlackBerry users. The company has set up "free calling zones" in over 40 countries where users can make free international phone calls. In locations not included in the free zones, Raketu charges a cheap calling rate.

Skype also offers a mobile version of its software on the Nokia N800 Internet Tablet and smartphones running Windows Mobile 5.0. Last August, Shape Services, a software provider for mobile platforms, launched a version of Skype for the iPhone. In the U.K., Skype last year launched a customized cell phone developed jointly with wireless carrier 3 Mobile.

Then there's a startup called Jajah that allows its subscribers to initiate VoIP calls directly from their mobile phones or computers by entering their numbers and the phone call recipients' numbers and hitting the "call" button. The calls travel over Jajah's servers, and subscribers are connected with the numbers dialed.