No need for a Computer to charge!!
OK, I've explained his simple thing to like 4 people I know now who have Cam's and always whine about having to leave the computer on to charge the Cam,.. or that they want to go out and waste $$$ on external type chargers.... This is SOOO simple they all laughed after I explained this to them. dumbA$$ video, but you'll get the idea
Trail Tire TV: Charging Cam's without computer
Yes, but before you install yourself on that high horse permanently, not all USB ports have the charge capability. And not anywhere near 80-90% of people have a DVR. I don't and my Dish box doesn't have an USB port on the front. Since the charging standard came out it 2007, I'm not sure if my very early 2008 TV's USB ports would offer a charge, either.
And an even simpler answer is for folks to check to see if they have a "sleep and charge" USB port and if so, enable it. That'll let the computer sleep yet still allow a device to draw a charge through that port.
And make no mistake, your DVR is ON. Just because you pushed the power button doesn't mean you've turned it off. The display goes off and it doesn't pump a signal to your TV, but that little computer is powered up and sucking a fair amount of electricity.
So it's not quite as easy as you think. And just to make sure I wasn't talking out my ass here, I plugged my Contour into the USB port of a brand new BluRay player (fully powered off) and no juice. I didn't bother to power it up to see if its port is a charging port or not, because I've enabled my sleep and charge capability on my computer.
There are "hot" USB ports everyone. We never shut our computers off, so that rarely presents a problem. We also have the ipod/iphone USB blocks that plug into the wall that can be used. All this said, I like your idea of using something like this. Especially if it is going to be siting around and could be used otherwise.