They had a kids tri the night before my tri last weekend (200yds pool swim, 1/2 bike, 1/2 run). My older four boys did it and it was so FUN!! They aren't really strong swimmers, but they did it (well, except for the 4yo who did a run through the kiddie pool)! I ran my butt off trying in the transition area (dh was at a work bbq), but it was so worth it to see them cross the finish line! You are right, THIS is what its all about . . . sharing something you love with your kids.