Skype mobile for the iPhone has now launched, and the much-anticipated Skype app for the BlackBerry is coming in May. There are some differences between the two. The BlackBerry will get the Skype Lite version, that will actually support both 3G and WiFi calling over the BlackBerry, the iPhone is currently restricted to calls only over WiFi. However, some other features for the BB will not be present (at least immediately), including file transfer support, and voicemail. Skype for BlackBerry will initially only support the Curve and the Bold.

As part of Skype’s plan for mass integration, the company recently reached a deal with Nokia to have Skype preinstalled on the upcoming Nokia N97 when it ships. Skype’s next plan is to release a version for Palm’s upcoming Pre Web OS powered handset, followed with other standard versions for other platforms.

Skype for the iPhone pictured