I have a new Sleep Science Memory foam mattress on the way and am wondering if I should buy a protector for it. If so are there any that are recommended here? Is buying a waterproof one necessary? Thanks.

 I was just looking into this too!  Protect-a-Bed has a waterproof pad that is well reviewed on amazon and qvc. It's 100% cotton terry cloth, so it's supposedly soft and not vinyl-like like most waterproof pads.  I just ordered a latex mattress and although haven't needed a waterproof protector, I'm afraid of what could happen to the foam if the dog or kid has an accident.