I carry a 4 3/4" Coleman fixed blade in a Nylon sheath on my belt. I don't wear it to school obviously but I do anywhere else.
Technically a blade length of 4 3/4" is legal so why not?
I love it when someone pulls out a 3" folder, and I can take my knife out and pull a Crocodile Dundee ("That's not a knife. Now THAT'S a knife.")