I couldn't agree more. In an earlier post you mentioned burpees, those are top notch. A burpee-sprint combo does wonders.
burpees are topnotch
try this with your burpees
1) Chirpees- youtube search that- they are pretty cool
2) tabata style burpees.....unreal
3) find a short hill/stairs/ incline. Run up that hill, do a burpee, jog back down. Then, run up the hill again, do 2 burpees, jog back down. Run up the hill again, do 3 burpees, jog back down....you see the pattern. Go up to 8-12. good workout