Screen Saver Passwords

Is there a way that when I walk away from my machine and the screen saver kicks in, to make it ask for a password for the person that steps to my machine again? I want to put a password on my IMAC, not for logging on, but for when I step away from the machine.

Thanks.

In system prefrences go to security. There you'll find a checkbox for "require password to wake this computer from sleep".

There is a way. I think it was in the Screen Saver preferences in 10.3