Product review (5 stars): Earthquake Straps for Water Heater
These installed easily and seem very solid.  I got an estimate from a contractor to install my new water heater, and they were "very proud" of their work.  I'm an average DIYS person, and I did the job with some help from my son (he's good with a wrench.) These straps are reasonably priced and good quality.  The screws drove in easily with no pilot hole.  Too easy to install to pay someone else!!