Ordinary batteries are cheap, plentiful, and probably incompatible with your modern gadget. IOGEAR’s new GearJuice Rescue Charger is a small device that accepts a AA battery and gives you a mini USB plug to connect it to your phone, music player, or anything else that charges from a mini USB connector.

We like the GearJuice Rescue Charger because it weighs less than an ounce, and costs less than 15 bucks, meaning you can stash one in all your glove boxes and bags.

But we don’t like that it only provides about 15 minutes of talk time, according to IOGEAR, meaning it’s probably a bit less than that in real-world use and even less if you have a smartphone that’s getting data at the same time.

Still, it’s better than being forced to buy a car charger at retail ($30 at Radio Shack vs. $3 on eBay) when you’re in a bind and need to make a call.

If you want to try turning the world upside down, pair a GearJuice Rescue Charger with a USBCell battery… great success!!

Price: $12.24 from Buy.com (even though IOGEAR lists the price as $11.99 on its site, Buy.com is the cheapest place to get it).