I would love to be able to carry a switch blade. One-handed operation!
Takes a good bit of practice, but the "butterfly" blade is one handed. Quite a display watching someone who is really good work it. Picture a Leatherman tool with the blade folded inside the two handle halves instead of the pliers.
The puritan reference brought to mind an old Andy Capp comic strip. (Bit of Puritan there. Really witty English comic, rarely seen any more. Most papers dropped it after the domestic violence people got outraged. Andy and wife Flo would betimes roll about like Beetle Bailey and Sarge.) Anyway, Andy, speaking of his mother-in-law once; "She's the sort would have people arrested for walking around naked underneath their clothes."
The Gerber "Gator" is the easiest to learn the "start with the thumb and flip of the wrist" method. The "old reliable" Buck knife works well too but takes a little more practice.
I've always have carried an automatic knife......
Any well-made modern knife with a thumb-hole or tab can be opened one-handed as quickly and easily as a switchblade