Skype for Android just received an update with a pretty big change. Two way calling is now supported on a wider variety of Android handsets. Previously, two way calling on Skype for Android was only supported on four devices, the Nexus S, HTC Desire S, the Sony Xperia Neo and Sony Xperia Pro. All these four handsets shipped with Android 2.3. Now with recent phones from HTC, Samsung and Sony Ericsson (except the Arc), you should be able to access two way calling on Skype for Android.
Now more with video
To be able to use two way calling on Skype for Android to full potential, you need to have Gingerbread as your OS. Froyo only supports the rear camera (and not the front facing camera), which might make life a little difficult when you're video chatting on your mobile phone. The update is available from the Android Market where you can also find a full list of supported phones in the “What's New” section.