Very Basic Question (I think) about AC/USB adapters

Hi,
I have been trying to find an adaptor that will allow me to use a USB outlet as a power source for some of my electronics (not including iPad, iphone, etc). For example I have a iPod docker that has an ac or dc adaptor that you can plug into a conventional socket. What I would like is the same adaptor but instead of it plugging into a socket, for it to plug into a USB (so I can use a portable USB powered battery). I have been looking for something like this but cannot find it, but perhaps I do not know the name of such a device so that is why I have trouble finding it.
I hope this makes sense, but let me know if I can make my question more clear.
Thanks.

GD_SYR said:

What I would like is the same adaptor but instead of it plugging into a socket, for it to plug into a USB (so I can use a portable USB powered battery).

Click to expand...

Not possible. USB can't deliver enough power.

There are USB iPod docs etc. available. Buy one of them.

What do you mean by "so I can use a portable USB powered battery"? A battery that you can charge from USB? For what device?

Sorry if I was not clear. I am not asking about a battery I can charge with a USB- but a portable battery that has a USB port that I can run a device on-i.e. like "plugging it into the wall"- except instead of a socket in a wall, a usb plug into the battery/power source. I am not concerned with how quickly the battery will lose charge, just the ability to connect the ac/dc cord to the USB.

New Trent makes all sorts of portable USB chargers. I use an iCarrer 12,000 mAh when I'm on the road. Handy.

I have one too, lol. What I want to do is run something from an ac adaptor with that (the iCarrier) as the power source, but I cannot find a cord that has the connection from this part of an electronic (such as a radio with a detachable power cord- the part that plugs into the radio) and the other side of the cord with a USB, instead of a traditional plug for a wall socket.
This may not exist ... but if it does I would like to know where I can get one.
Thanks!

You want 120VAC out of a USB port? Nope, not gonna happen. It could be done but would be woefully low current. You could drag around a UPS but they're not exactly portable.

How big do those come? and how much/ballpark?

UPS's are dirt common, they usually contain a big heavy SLA battery, a basic one can be had for $30.

What exactly are you trying to make portable?