AAA has saved my bacon more than once...and on our most recent trip (8/26-9/3) absolutely paid off in spades.
We drove to WDW from Jersey. On the drive home, just an hour from our night's stop in Florence SC, we blew a tire at 70mph. Hubby had no trouble getting the car off the road, but it was getting late (7:15pm) and we'd never changed the tire on this car before. Plus, I'm not a fan of changing tires on the side of the interstate, two kids, blah blah.
Anyway, the SC Highway Patrolman who pulled up behind us almost immediately offered to call in AAA for me, as she said they'd come faster if she called. Sure enough, within one hour our tire was changed and we were on our way to the hotel. If I'd had to pay for that service call (Saturday night of a holiday weekend) I have to believe it would have been at least $125...more than the cost of my AAA membership!
If they want the number now (and many hotels, not just WDW, have asked for the number ahead of time when I've made ressie's) get the membership now and enjoy the peace of mind right away.