The new version of AutoCAD WS mobile for the Google Android platform devices such as the Android phones and Tablets is now available in the Google App Marketplace. It looks really nice on the Tablet devices where you have more screen real estate. There are some Android unique features in this Android version such as speech recognition where users can insert comments and text notations in the drawing by speech rather than typing.
YouTube Video: AutoCAD WS for Android Video
Direct link to AutoCAD WS mobile for Android in the Google App Marketplace https://market.android.com/details?id=com.autodesk.autocadws&feature=search_result
One thing they all have in common besides DWG viewing, editing, and markup is that they are all FREE.