This is probably going over everyone's head, but I just saw this on the eBay deals page. A rechargeable USB battery pack that has ports for both 1A and 2.1A outputs. I don't know how consistent the output is, but it peaked my interest because my Asus WiCast (streaming HD video) requires 5V 2A minimum to run, or it's just not going to power up. Right now I have everything working nicely with the Tekkeon battery packs, but they are a bit large to mount with camera.
I tried a number of other USB battery packs for the 5V output, but they just didn't put out the 2A that I need. Maybe this one is different? The Asus probably needs the most amount of power, but if you're using something like the Brite-View HDMI wireless systems, that should that requires less. Anyways, I guess I might be the only one excited for something like this, so just ignore this post, but if you're shopping for a portable battery pack for anything else USB powered, it might be something to look into with the price drop (click here).
Vaas VM50 5000mah 2.1A USB 5V Rechargeable