BlackBerry phone owners can now talk to each other with free BlackBerry Messenger (BBM) voice calls over Wi-Fi.
The new BBM Voice feature for Research in Motion's chat service goes live in BlackBerry App World today, although it may take 24 hours to appear in the storefront. It's available for all phones running BlackBerry 6 OS or higher, with support for BlackBerry 5 OS coming early next year.
To make a voice call, both BBM users must be connected to a Wi-Fi network. A green telephone icon appears in the top-right corner of the screen. Tapping it initiates the phone call.
Users can still go into other applications while a voice call is in progress. They can also go back into BBM to send written messages or share photos.
It's not clear why the feature works only over Wi-Fi, and not on 3G or 4G networks. Apps like Skype, Tango, and Fring, as well as Apple's built-in Facetime app on the iPhone, are all allowed to work over 3G and 4G networks now.
In any case, BBM Voice probably won't lure many people back to BlackBerry in its current state, but it could be a nice feature to have on a BlackBerry 10 handset. The overhauled OS is finally on track to launch in early 2013.