In order to view your videos and presentations on a large screen, you are going to need a decent projector. The 3M Streaming Projector w/ Roku is more than a simple projector though. It is portable and very compact. It can show pictures up to 120-inch wide. You get a portable Roku streaming stick that lets you see content from Amazon, Netflix, Crackle, and many other sources.
The stick connects to your internet wirelessly. The rechargeable battery runs for 2 and half hours, which is not awful for a portable home theater. You can get kit for $299.99.