Something new for this year's Leadville 100 Mountain Bike Race is athlete tracking. Keep in mind it's not exactly "live" - don't think follow someone like GPS tracking. Rather, the athlete tracker will tell you when the athlete crosses certain points on the course.
If this system is like others I've had experience with - don't panic if you can't find your athlete on course. There are often glitches in the system and I can't imagine the challenges on a mountain bike course like this one.