[Henry_Mareck]

Personally, i usually carry a Multi-tool with a knife on it, and I use the knife almost as much as i use the phillips head on it. I never have had any problems with any administration or rules, but i generally don't wave it around. Depending on the way you school is run you may or may not be able to do the same thing.
A bike tool is a good idea, because knifes are not too useful in the fixing of bikes, so they are less likley to have one.
and i have to add: A chain break on a multi tool? Awesome!