I did this in HS way back when. I thought it was a lot of fun. There are increasingly selective rounds as you go up the ranks. IIRC, the judges at each stage were American Legion members. The theme is usually patriotic. I think I did mine on flag-burning. There are nonmonetary prizes along the way -- dinners, plaques, and such (think I might even have mine around here somewhere ::rummages::
) all the way through state and nationals. I didn't win nationals
but met a lot of great and talented kids along the way.
Once identified as a "winner," you are usually asked to do some other public-speaking things as well (at least I was). For the local Memorial Day celebration, I remember being asked to memorize and present the Gettysburg Address (which I can still recite to this day). I was also asked to judge some public speaking contests.
Don't know how much or if it helped with college admissions, but I got into everywhere I applied and went with the one who gave me the most money (which was a tidy sum).