my waters didn't break until i had been in active labour for over 16 hours and was pushing my daughter out. i was sitting on the toilet at the time, and they broke in the middle of a contraction and were squirted at such high pressure into the toilet bowl making a most almighty noise!! neither myself or my DH (who was sitting with me at the time) knew what had happened, and he said " oh my god, is the baby in the toilet?!" ha ha...
i had been prepared with waterproof mattress protectors and towels on my mattress and in the car since about 35 weeks (i didn't go into labour until 42 weeks!), and didn't need any of the precautions in the end... this time around, it hasn't even occurred to me to try and protect anything!!