I'm a 44 year old woman who considers herself pretty careful/responsible.
I have broken both my Iphone 4s, and my Ipad2. The Ipad happened first, and just slipped off the dresser when we were watching a movie(had it hooked up to the tv), this was back when Apple was still doing free replacements, so I got another Ipad free of charge.
About 6 months later, my DH dropped my Iphone facedown on the floor, it was in a case (a really cute mickey one), but the screen still cracked. Fortunately I had applecare on that, so they gave me another phone for $50. Now the Iphone is in an Otterbox case. It has even fallen out of my pocket while jogging and just bounced off the street.
The Ipad is now in a Griffin case (heavy duty like an otterbox).
So apparently it's not just the kids!