Sardu allows you to easily combine many different bootable images on one USB stick, without the fiddling required to build such sticks manually.
This video is a basic walk-through of downloading, running and testing a Sardu USB stick. Pause the video at anytime if you're following along.
Sardu is available to download from http://www.sarducd.it/downloads.html
See this other vid if you don't require multiboot, need a persistent install, or Sardu just isn't working out - • How to create a bootable USB stick with Li...