OFFICIAL ANDROID DESIGN SITES
– Android Design Guidelines
– Android Developers Blog

RECOMMENDED SITES THAT DISCUSS ANDROID DESIGN
– Android UI Patterns
– Android Niceties
– Android Development
– ICS-Apps
– Styling Android
– Android User Interface | User Experience
– Android Patterns
– AndroidDevBlog
– Vogella
– Android App Patterns
– Android Samples

ANDROID DESIGN PRODUCTS
– Android UI Stencils

HOLO DESIGN BACK-PORTING TO PRE-4.0 DEVICES
– HoloEverywhere on Github
– ActionBarSherlock