Instructions
Go to the "Home" screen and choose "Settings" (the briefcase icon).
Choose "Security Settings" (the lock and wrench icon) and press the "X" button.
Scroll to "Internet Browser Start Control" and press the "X" button.
Create a four-digit password that must be entered in order to use the PSP's Web browser.
Scroll to "Internet Browser Start Control," select "On" and press the "X" button to confirm your choice. Now, the Internet on the PSP is blocked to anyone who doesn't know the password.