I just came across a quick guide to splinting in the Emergency Room and thought a lot of people might find it very cool. The guide is from a wonderful blog called ERCast.org.
The videos guide you through the application of both upper and lower extremity limb splints. Thumb spica, ulnar gutter and lower limb stirrup are looked at in this series.
Make sure to check them out!
Here is a link to one of their videos: