Chop,
I don't have kids personally, but I have a lot of little buddies and or adopted nieces/nephews. I've never had a problem. I've carried Izula, Izula II, ESEE-4, BHK Boattail Scandi, Kellam Aito Puukko, and an ML Kephart (that I can think of) while playing with and totally horsing around little ones. Never had a little one reach for a blade, and if they did, its time to swat some hands.
Be safe and God bless,
Adam
EDIT: A nice deep sheath like on the BHK Boattail Scandi or the likes of the ML Kephart Sheath, are easily the best, the BHK being slightly better IMHO (less for the wee ones to get their hands on.) Also, just teach kids responsibililty. They are much smarter than we give them credit. And if you are willing to tell them "No" and let them know you mean it, they'll learn quickly.