Allow for locking of view modes in Viewports

In any view you have Blender in, you're able to rotate out of that view (either purposefully or accidentally). However a lot of times, you'd like to switch from say top view to right view, and not have to worry about finding yourself in perspective mode. There should be an option to allow for locking of orthographic views so that they're not rotated away from accidentally.

Ideally, an option in user preferences to either have that behavior on or not.