My first thought was to spread the media around, some on my iPad Air, some on my wife's iPhone 5S, some on my Moto X, etc. That was going to be confusing at best.
Then in my Deals RSS feed popped up a RAVPower FileHub. It's hard to explain what this gadget does. I'll start with sharing the description from Amazon.
RAVPower FileHub Built-in 6000mAh External Battery Pack & Charger with Wireless N Portable Pocket Travel Router, Wireless Micro SD TF Card Reader, Wireless USB, Wireless Flash, Mobile Storage Media Sharing, WLAN Hot Spot & NAS File Server
It's got a connector for everything and it weighs 5.5 ounces. Its size is 2.9 x 2.8 x 0.9 inches.
I had been looking for a battery pack for my mobile devices anyway and my travel router is only 802.11g.
This seemed like it was too good to be true but it all seems to work.
I found an unused 32GB microSD card in my stash to contain the media.
It came already charged and when I turned it on it presented a Wi-Fi network named "FileHub-XXXX". You can connect to this with your PC with a password of "11111111". There's a web UI (10.10.10.254) that will let you update the firmware and configure the device.
There are iOS and Android apps in the respective app stores. Not only can you stream media from the microSD card to your Wi-Fi device(s up to 5) but the app has a player for media already on the phone or tablet. From your laptop browser just go to 10.10.10.254 and there's a media player served from the device.
If you give the app access to your device's media, you can download the media from the device to the FileHub using either the microSD or an external USB drive. Similarly if you access this from your laptop browser you can download files from the laptop to the FileHub using either the microSD or an external USB drive basically making it a microSD/USB adapter.
All this worked perfectly and I haven't found anything that it won't play although pretty much all my media is H.264.
I flashed the firmware to the latest rev.
I have used it as a Wi-Fi WISP device bridging my Wi-Fi to another SSID with NAT in the middle. Just what you need for Starbucks. It will also function as a pure NAT router generating its own SSID from Ethernet input.
The charging output is 1A so it probably won't do well charging an iPad.