Thank you both so much for your answers! zoiDman, so I could use PCCs for cell phones/notebooks on Riva/eGo batteries? Where would I get one of those? Or if I were to look on Amazon or something, what would I search for? Thanks!
The external battery I got is kinda overkill for most people. I bought it on e-Bay new for $25 so it was a great deal.
Amazon.com: Digipower Rechargeable Battery for Laptops and Mobile Devices EBP-NB60: Electronics
I got it for a week camping trip I went on. Most people want a PCC to be able to charge a e-Cig battery when they are away from a way charger.
But here is the thing. If you are just looking to charge a e-Cig battery once or at most twice while about and about, it is probably cheaper to just buy two more e-Cig batteries verses a PCC.
If you do decide that you want an external battery to be able to charge e-Cigs and or a cell phone/iPod, you might do searches for "external USB batteries" or "USB batteries. You going to get many results. Look for ones that say they have 5v usb output with at least 500mAh. Your looking for a external battery that has USB port on it for output. It is just like using your computer usb port to charger an e-Cig.
The amount of storage capacity the external battery has is also measured in mAh. If you divide this amount be how much your e-Cig battery has, it will give you a rough idea of how many times you can charge your e-Cig.
Example: A standard eGo/Riva battery = 650mAh. You find an external battery that says it has 2,400mAh capacity. 2,400/650 = 3.69 So you could recharge a eGo/Riva battery 3 times before the external battery needs to be recharged.
Like I said, it might be cheaper just to get a couple of extra e-Cig batteries. But it is nice to be able to charge a cell phone and an e-Cig if your going to be gone for a couple of days.
A portable USB charging device of any kind should work, you can also buy specific models for the electronic cigarette of your choice.
There are tons of PCC 's made for most "pen" style e-Cigs such as 510 or KR808. I have never seen one for a eGo/Riva though.