Aaron Dunlap is selling these excellent USB 9-Volt charger kits in an Altoids tin for the ridiculously low price of $9.50. I can't think of a better stocking stuffer.
Update: Aaron Dunlap says: "I should point out that what I have for sale is kits to build your own charger in an Altoids tin or whatever you want. You get the electronic components and a walk-through manual. You might want to mention this on the site, since I've had a lot of people place orders thinking they're getting the whole kit & cabootle when I don't have the time to solder together 300 cabootles."
Reader comment: avidd says: "I call prior art on that USB charger featured in today's post. I built one for my trip to the amazon rainforest. While the guy is providing a service by selling the kits for cheap, he's being silly about keeping the design so mysterious. Buy a 5v IC regulator like the NTE960 or NTE977 from jameco.com for $1.65. Solder it between the battery leads and the usb leads. Don't forget the matching heatsink. For the NTE977 I chose to put some capacitors to ground as recommended in the manual on page 8 though that might have been overkill.
"That's really all there is.
"Go ahead and sell the kits, but Information wants to be free. Link
Reader comment: Aaron says: "Why does McDonald's stay in business when you could just make your own burgers? You can even get cookbooks for free from the library.
"Information should be free free; parts, however, aren't. My kits are
meant for beginners who wouldn't know how or where to get the parts
themselves or what to do with them. I have the full manual posted online
if someone wanted to just
do it themselves."