Get an iPad or Android tablet - then add a wireless drive like this:
http://www.amazon.com/gp/product/B00...ZQW4BOELMARYBP
It'll add 500GB for just $99, plus you can then share that with others. Upsides are easier loading of content (loading your own content onto an iPad can be a pain), and of course way more storage space. Add a $20 Anker battery pack, and you'll be good to go for the entire flight.