I have the current version Mountain Lion and set the Screensaver to 30 minutes, but since I am the only person that have access to this computer, I would like to turn the password off, but there seems to be no such method?
If you turn on FileVault then the checkbox disappears, so your only choice is how long it will take before you need to enter a password. I found this so irritating that I turned off FileVault altogether. Then the checkbox came back and I could get rid of that option.
What is also strange here is that when you have FileVault on (and thus have no choice about having to enter a password) the maximum time is 1 hour. When you have it turned off, not only can you turn the password option off altogether, you also have a maximum grace time of 4 hours.