I used to be able to run for hours w/o music... and now with an ipod.. it makes all the difference. It gives me that last bit of I CAN DO THIS!!! when I am just about tapped.
Please don't think this is said in a mean way... You said you are gonna run it in 5 hours, which still makes you a kick a$$ runner, by running a marathon, but not in the elite, I'm gonna win a money prize runner. It is a little easier to go for 2 or 3 hours w/o music than 5 or 6... plus at the end.. you aren't really moving at the speed of those that will trample you. Just be sure to start out w/ people in your pace group... and you'll do fine WITH or WITHOUT an IPOD.