The two ways I see to secure an Android phone is through a PIN lock screen or through an app lock program (Password is too inconvenient and pattern is insecure for various reasons). The lock screen has the advantage of keeping someone from the phone altogether, but an app lock program can allow me to use basic functionality while locking the apps that I choose such as Email or Package Installer.
Is one option easier to hack/bypass than another? Let's assume that the App Lock program has a helper app that prevents it from being killed (although how well such an app works is worthy of being discussed in an answer - point being it takes a little more work than simply going to task manager and killing it).
I am primarily concerned about data on the phone.
I know that ultimately I cannot rely on either method to secure the phone indefinitely, but to only secure it long enough for me take various actions such as remote wipe, change Google password, Exchange password, etc...
I'm running Gingerbread 2.3.6. For what it's worth it is rooted and has ClockWordMod recovery.