I run with my Border Collie using a lead and a harness rather than a belt/bungee. But as MR says I also let mine off once we're off road. I read a bit about it on the cani cross site and on one of the BC boards the aim is to praise when your dog is running out in front using a key word such that you can then use it again if they lag/loose concentration in the same way you would treat any obedience exercise.
I think breed does make a difference in that Lexi is very focused when we're running and doesn't tend to stop to mess with other dogs and gets quite cross/noisy if I stop (she's struggling with the concept of intervals!!) however my last Collie thought running was a mugs game as there was no ball to chase and would frequently lag behind even if off the lead so just having a collie is no guarantee of focus!
Have a look at the Cani cross website for some info on equipment and techniques when running with dogs.
Not sure about ipod classic, but fairly sure my ipod nano has been damaged by me holding it in my sweaty little hands while running. The scroll wheel is very tempramental, the screen doesn't work too well and there have been various synch issues over the last yr or so. Once it finally dies I'll probably use my iphone but carry it in a plastic bag as I read on here somewhere last week to keep the moisture away from it. They are probably better protected if you use one of the arm band thingies
Have found this early morning thread really good motivation to get out early doors, as someone who has generally been an evening runner in the past, esp as my main reason for running now is to fit in exercise with walking the dog (Border Collie - she always wins LOL)!