Google acquired Android Inc in 2005, so development had started before Sun opened up Java, see http://en.wikipedia.org/wiki/Android_(operating_system).
The Guardian Project aims to create easy to use apps, open-source firmware MODs, and customized, commercial mobile phones that can be used and deployed around the world, by any person looking to protect their communications and personal data from unjust intrusion and monitoring.
Here is a link to their February project update to give you an idea what they are working on: https://guardianproject.info/2012/02/09/february-2012-project-update/
Encrypting mails you send via webmail without having copy your keys on the server sounds like reasonable usecase.
"What people have been reduced to are mere 3-D representations of their own data." -- Arthur Miller