Free Skype for Android client allows voice calls over Wi-Fi connections in the U.S. and over mobile data or Wi-Fi connections elsewhere Android smartphone owners can now download a free Skype client from the Android Market that will let them make voice calls over mobile data or Wi-Fi connections — except in the U.S., where it will work over Wi-Fi only.With the new application, smartphone users can make free Skype-to-Skype calls, unless their network operator makes additional charges for data usage. The app will also allow them to communicate using instant messaging and make calls to regular phones for a fee.[ Stay ahead of the key tech business news with InfoWorld’s Today’s Headlines: First Look newsletter. ] The app works on smartphones running Android version 2.1 or 2.2. Skype tested it on HTCs Desire and Legend phones, Google’s Nexus One, and Motorola’s Milestone and Milestone XT710.The application may also work on other Android phones, Skype said, but it won’t guarantee full functionality or compatibility. It is aware of some problems with the app on the Samsung Galaxy S, which it will address in the future, it said.Users that have already created a Skype account on a computer will see their full contact list when they sign in to Skype on their Android phone. The app can downloaded from the Android Market, except in China or Japan, or by directly accessing skype.com/m from a compatible smartphone, Skype said.The company didn’t say why U.S. users are only allowed to use Wi-Fi to make Skype calls.Send news tips and comments to mikael_ricknas@idg.com. Technology IndustrySoftware Development