I bought a Samsung 70/300 lens for my Rebel and it's just the thing! I absolutely love it! I can get right in close on his face, see the beads of sweat and water, and the sport mode on the camera allows me to get the perfect shot of his acrobatics. It also allows me to be "Super Stealth Photographer" at gatherings and events and get great shots of people when they don't know you're there. Gotta love the candids.
This is a layout I did using one of my favorite shots of him wakeboarding. I like the juxtaposition of the lines in the photo vs the lines on the paper.
A little bit closer still. He must be preparing for a trick, judging by the concentration in his face.

