Snap to grid toggle and space bar

I may be missing a key short cut for this that already makes this possible, but a key press that functions as a toggle for the snap to grid feature would be great. Much easier than going into preferences to tun it off for a single operation and then back on.

Also, a special request for the Lightwave users out there, how about making the space bar toggle through vertice, faces, and brush editing states, similar to the way light wave toggles through points and polygon editing states.