I have an Acer Aspire One AOD250 which comes with a dual-booting system with Android and Windows XP. When I boot into Android, it goes straight to the home screen without any verification of my identity, unlike Windows requiring a user password, or the funny grid that you get on some Android phones.
I want to ensure that if it gets stolen, that someone can't just turn it on and start reading my emails, etc. How do I do this?