Is there any way to access some apps before I put in my password? I have a 4 digit passcode for my iphone, but there are some apps that I might use frequently that don't really need to be protected.  Is there a way to access those apps without entering my passcode every time?  An example of such an app would be the calculator or calendar apps, or even the Pandora app.

Any ideas?
No, although there are/were tweaks available on jailbroken devices that enabled locking specific apps with a(n unrelated) passcode.