The new version of Yahoo Messenger enables users to make video calls and stream live video one-to-one over 3G or Wi-Fi. What makes the app really interesting is the ability to establish a video call between an iPhone and an Android device (provided it has a front-facing camera) or between an iPhone and a PC.You can also make free voice calls to your Yahoo Messenger friends, as well as low-cost international calls with your Yahoo Voice Phone Out account. Unfortunately, this last bit is available only to users in the U.S., France, Germany, Spain and Singapore.Finally, the new version now supports multitasking, meaning you can work on other tasks on your iPhone while the app happily runs in the background.