A lot of folks have been talking about the Spyderco Native. Don't know the blade length, but it appears to be a smallish blade. I've never worried too much about being in the ballpark, if you'll excuse the expression. The only time anyone raises an eyebrow is if you have to go through a metal detector. I did, once, in a federal building, and at first the guard refused to cut me a break, which meant hand over the knife or leave. But when I explained it was my grandfather's Case knife, he waved me on through.
You'd only get in serious trouble if you pulled out a 4+ incher in a very restricted area and even then you'd probably only lose the knife. I've been to see school plays with a 6-inch Voyager in my pocket. That could get me in trouble, but you know what they say about discretion!