If like us you have a puppy who still insists on pulling on his leash at times, then I'd highly recommend the Comfort Cushion Leash by Aspen Pet.
Don't worry I'm not on commission or trying to sell you anything, just wanted to pass along some wisdom in case your hands are suffering from all those walks with a powerful pup.
We've just bought Cooper's third padded leash (he's nearly chewed through his black one, so we needed another), so now he has a nice purple four foot leash (for street walks) and a longer six foot leash (ideal for running along at the beach).
They are double-lined, so not only are they kind on your hands, but they are more resilient and do survive puppy teeth for longer too!
The padded handles are great because I find that with the Californian dry heat and dusty winds, I get sore and cracked hands, so the last thing I need is for them to be aggravated by a coarse nylon leash (which has happened in the past).
The padded leash is available at Pet Co, but oddly I've not been able to find it at Pet Smart stores.
Cooper's growing up because we also had to buy him a new dog collar today. It's not as spiffing as his studded leather one that was a present from family in England, but it'll do for now (and at least we're safe in the knowledge he'll be able to breathe comfortably).
And that's my sage advice imparted for the day folks, if you have a big dog like our yellow Labrador (Cooper is over 70lbs now and his father was around 100lbs full grown), I totally recommend this leash.
Damn, if only I was on commission think of the money I could make...