Ah! I figured out something from the technomacy blog post. The last part says:
Adapting the build process to Duby was surprisingly easy. You redeclare the compile task to call the Duby compiler instead of javac, tell it to output its bytecode in the right directory, and the rest of it just falls into place.
Any link to get started running Duby on Android? Would be helpful to many hungry wannabe-android guys.
I thought I'll take a light year to learn Android dev. But Duby seems to bring some hope.