Justdeals
is currently offering the Marware Amped Portable Charger for $4.99 + $5 S&H. Your choice of black or silver. These go for $35 - $43 on Amazon depending on color. Didn't check prices elsewhere.
I bought one last June for just a few cents less from the same vendor and is still going strong. This time I picked one up for my wife. We use this for our iPhones and iPods. Mine lasts me about 2 charges which works great for me when my phone is low and I've forgotten to charge it. If I don't use it for a week it'll stay charged up fine, but I usually use it for one thing or another soon after. It's small enough to throw in my camera bag or pocket along with a sync cable.
When charging it can get a bit warm or even warmer when using your device at the same time. It does keep an iPad going, but not give a substantial boost, good for an emergency.
It does not come with a USB sync cable, just a USB cable to charge it. It can be used on other devices, but I can't vouch for anything except the mentioned above.
All in all it's handy to have around. On sale until tomorrow.
