When, in June 2006, Ubuntu Dapper Drake was released, it introduced a very exciting new feature: the ability to run it from a USB drive (also pendrive, USB bar or memory stick). This would work just like a LiveCD, with the big improvement that all your data could be saved onto the USB drive! This means not just your documents, but also e.g. network settings or your desktop background. You were practically carrying around a fully-functional operating system on your USB drive!
MPlayer is a movie and animation player that supports a wide range of codecs and file formats. It also has a plugin for Firefox allowing you to view streaming video from your web browser. This short howto will help you get it up and running in no time.