There are several different blade lengths and several different models of assisted openers.
There are lots of options, even if you can only carry a sub 2 inch folder. And they are really reasonably priced.
I recall that in some state I lived in, it was legal to own a switchblade - but only if you were missing an arm! I saw one that I liked in a store in Atlanta - and the clerk said "you can't carry it, though". So I asked her, "so how do I get it out of the store"? The clerk just got totally confused. The girl I was with though that was pretty funny...