Nice video, John! Mountain biking was the first sport that I got into after quitting pole vault the first time around. It is great in many ways but is expensive and easy to mess yourself up. Freeriding requires a certain kind of bike that can take huge drops ($$$), but just regular cross-country mountain biking can be done with an average bike.
Paddling is another great sport...canoe, kayak, stand-up paddling...it's great to be on the water and good upper body/core exercise. Not much whitewater in Illinois, but you've got lots of rivers and lake Michigan is great for sea kayaking.
My favorite sport other than pole vaulting is bouldering...rock climbing on relatively short, technical climbs with no rope or harness. Climbing 20' high boulders and committing to the top-out is almost as exciting as clearing a high bar. Not to be outdone by master, I figured I should post a video:http://www.youtube.com/watch?v=Y1cGseVcG2A
There is a lot of excellent bouldering in Southern Illinois...part of the "sandstone belt." Not sure what part of Ill you are in, but there is also great roped climbing at the Red River Gorge in Kentucky and also some at Devil's Lake, WI (N. of Madison). Climbing at an indoor rock gym will give you an idea if you like the sport; you can rent shoes and a chalkbag without having to make an initial investment. If you like it, shoes are $100-150, chalkbag $20, and pad ~$100-$200...it's free once you get this stuff. Many climbers who live in the "flatlands" train during the week in rock gyms and take trips to climbing spots on weekends. Do a search on Illinois climbing to find areas near you, or use these links. http://www.rockclimbing.com/routes/Nort ... /Illinois/http://www.ilclimbers.org/pages/area_overview.html