Finished a 20 miler this past weekend with a great rechargeable battery for my Verizon iPhone. If you aren't the type of runner that uses GPS for any of the apps they use for running, this might not mean a lot to you, but for everyone else, this should be good information.
I've found that my iPhone/iPod can usually last 2-2 ½ hours on a full charge if I'm using my GPS. I use the RunKeeper app for my long distance runs as it is pretty reliable on the mileage tracking. But as we all know, the GPS on any phone just drains it at double the rate of normal use. So I have been plugging in a reserve pack for any of those runs going more than 2 ½ hours. But no need to with the Energizer AP 1201.
The battery bills itself as giving your iPhone double the battery life. But I found that you actually get more than that, probably 5 ½ to 6 hours life. What I really like is that it's a silicon case that also protects the iPhone. If you get caught in a quick rain, it's nice to flip the phone in a pocket or on your sleeve so that it isn't getting water directly, which just kills an iPhone.
One of the other advantages of the unit is that it you can plug your iPhone into it, then plug both them into a wall socket and charge them both at the same time (no charging them individually). The iPhone automatically charges first, and when it gets full, the unit then starts taking the charge, pretty slick.
Again, if any of you that need to take an iPhone with you on a long run (because of using a running GPS app, a phone to call for a pickup if you die on your run, or as protection in running in an unknown area) the Energizer AP 1201 is a great accessory. I would give it 5 out of 5 in this category.
If you are interested in buying this, Best Buy has them available at a discount price, but I found the best deal on Amazon for less than $30. See: