When I was a little shit I had a little switchblade keychain knife. It was pretty cool. Haven't seen one in years. I went on field trip to New York in 8th grade and the teacher saw me playing with it on the bus. She said "Did you buy that here?" I said "No my dad and I bought a bunch of them at a gun show in VT." She said "Oh. Put it away please." Those were the days.
ETA: Here ya go! I had this same knife.
http://www.myswitchblade.com/Italia...-Grind-White-p/italianpicklokkeychn3black.htm
That knife has a blade length longer than 2.5", but I believe Worcester make an exception of that rule if you have an LTC.