While browsing the clips on dslrflix I found this story of a kid who wants to box. The story is compelling and there are some very well edited sequences (when it switches the view from the father to the kid when talking about is health issues). Take a 3 minutes pause and check it out. It is worth it!
5DMKII video of youth boxer from David Stephenson on Vimeo.
The creator of the clip also made a great blog post giving insider information about how it was shot and outline some of the limitations of the camera (that all owners have unfortunately noticed by now!). There also a lot of other photography / video content on his blog so go check it out too!