Can anyone offer any links, books, or advice related to designing great user interfaces for Android apps?

I've worked my way through Hello, Android and found it to be a great starting point but I feel it was really lacking in basic user interface techniques. Stuff like: How do I put a custom background image on a button and handle state changes? What should I use to animate parts of Views?

So far I've found this presentation which has some pretty good tips:

http://www.slideshare.net/AndroidDev/android-ui-design-tips

and this collection of links which is mostly tool-oriented:

http://speckyboy.com/2010/05/10/android-app-developers-gui-kits-icons-fonts-and-tools/

Also related: does anyone use DroidDraw or similar tools? I'd love to her your impressions.