Thats some good stuff. I took TaeKwonDo growing up - its generally more sport oriented, but our club did a lot of self defense and grappling as well. I started when I was 5 and earned my black belt when I was 15, and then I quit when I was about 18. 5 years later I found myself in Korea (home of TKD) w/ the Army and was able to train w/ a well known Korean Grand Master - it was great! I'm by no means a fighter or an expert, but I think that martial arts played a large role in how I turned out.

The "Combatives" program that the Army teaches is mostly ground fighting oriented and is some pretty good stuff - if taught well (crappy instruction makes it worthless of course).