I've looked around but can't seem to find any good answers. Would appreciate any pointers.
How to launch screensaver with a keyboard shortcut
keyboardscreensaver
Related Solutions
You don't need to install any additional software.
Go to System Preferences > Keyboard > Shortcuts > App Shortcuts
Click the
button below Enter "Minimize" (use "Minimize All" to override minimizing all windows with ⌥⌘M) into the Menu Title text input field.
Assign some bizzare key combination that you won't press by accident.
Repeat steps three and four for "Minimise" (alternate spelling) which is required for some apps.
Close the window to save the changes.
I'm aware that this is not really "disabling it" but the result is effectively the same and without depending on 3rd party software.
You have to add it manually in System Preferences > Keyboard > Shortcuts > App Shortcuts
Best Answer
I don't believe there is a built-in, system wide Keyboard Shortcut. The quickest way to activating the screensaver via the keyboard is either via a "Start Screensaver" command using a launching applications such as Quicksilver, Alfred, or Launchbar.
The quickest way of starting the screensaver using your mouse is via Hot Corners. Open System Preferences, click "Desktop & Screen Saver", click over to the "Screen Saver" tab and click the "Hot Corners" button in the bottom left. There you can specify a corner to roll over in order to start the screensaver.
If you want to start the screensaver quickly, because you want an easy way to lock your computer, a possible answer is located in the high-view "Mac OS X Hidden Features Tips & Tricks" question that remains active.
And specifically, this answer.