Hi J.,
At that age I arranged the furniture so it was blocking the outlets, and outlets I couldn't cover with furniture I childproofed with covers that screw on because my kids knew how to unplug those little platic pieces. It seems like a bit of a hassle, but in comparison to loosing your little one to an accident, it's well worth it.
My mother loves to tell the story of how lucky I was to survive as a toddler. I plugged a pair of tweezers into an outlet, shorted out the apartment building we lived in, she saw what looked like a lightning bolt streak across the room, the walls were scorched. Lucky for me she liked expensive tweezers that had rubber grip handles and I survived with just a fear of outlets and electricity my whole life!