I could definitely see carrying the Cricket or Spin in a back pocket - no longer than the knives are, you wouldn't be sitting on them. FWIW, in-waist-band (IWB) carry has more to do with clip position than the size of the knife. For instance, I have quite comfortably carried a Caly3 IWB, but I could not carry the smaller BM MiniGrip. The Caly3 has a clip at the very end of the handle, so the knife sits below the top of the waist band. The MiniGrip's handle sticks out above the waist band and makes it uncomfortable to carry. YMMV.