Android Botnet : Command and Control Channel over SMS
Shmoocon 2011 Smartphone Botnets over SMS Demo from Georgia Weidman. Compiling instructions are simple and straight forward. Please follow these:

Compile with arm-gcc with the -static flag set
Copy to anywhere on the underlying OS that is writable (/data/ is good).
Rename /dev/smd0/ to /dev/smd0real/
Start the bot application
Kill the radio application (ps | grep rild)
The radio will automatically respawn and now the bot proxy will be working

More interesting stuff such as the botnet structure, possible infection methods are presented by the author in here slides that can be found here.

PDF
http://www.grmn00bs.com/GeorgiaW_Smartphone_Bots_SLIDES_Shmoocon2011.pdf

Download
http://www.grmn00bs.com/botPoCrelease-android.c

http://vimeo.com/19372118