Here in South Africa getting your knife confiscated is a real possibility. Depending on where you go (medium 4S correlation) the cops pull random stop and searches. Their pat-downs can be quite invasive (i.e they'll often feel your crotch) so simply hiding stuff down your pants might not work. Also it seems like the majority of the cops are either ignorant or just looking for a quick buck, so any knife is liable to get taken out of ignorance of the law or for personal gain, legality be damned. Like George Carlin said - the cops love it when you know your rights. Especially when they don't and don't care.

While I think a screwdriver is a decent enough weapon, when the cops find someone with a screwdriver (or any kind of tool really) you'll read in the newspaper about someone getting arrested with "housebreaking tools". It's the catch-phrase for "anything we can add to the charge sheet".

The higher caliber LEOs will probably arrest someone who's walking down the street carrying a screwdriver, but someone carrying a nice quality folder will get let go. It doesn't matter what the politicians say, the cops profile and are unapologetic about it.

Cops are a definite candidate for ditching/stashing here.

Bouncers etc. are a pretty standard affair though. Only ever had one make a point of looking at my hand that was holding my wallet out to the side and away from the focus of his attention (knife wasn't behind the wallet that time fortunately). I had to go back to the car once to drop off a flashlight because I wanted to experiment and see if they'd let me in with it. None have ever checked my shoes, and none have ever felt me up. Also any check of a woman's handbag tends to be very superficial - as in hypothetically they wouldn't a pair of full-sized pistols + spares + folders. Hypothetically. So bouncers you can usually by-pass - no need to ditch/stash.

Metal detectors seem to effective in inverse proportion to your ability to walk through them as if they aren't there and have an IDGAF look and attitude. Proper event security (stadium games, casinos etc.) tend to be higher quality and more effective (but a beeping metal detector tends to result in a pat down - a not-too-thorough pat-down). The casinos tend to have safes where you can check in a pistol. However once you're past the metal detectors (being escorted to the safes to check in your weapon), nobody bothers to make sure that you checked in all your pistols. Again, no real need to ditch/stash.

One guy I've trained with was stupid enough to walk over to a stop-and-search cordon and basically volunteer to get frisked (the "illegal weapons act" had just changed and he decided he wanted clarification). The cop called his friends over to check out the bowie. And then he was told he's getting arrested. He had to talk his way into seeing the station commander before anybody knew enough to let him go. If the station commander had been away from his office he would've been arrested and processed. I wouldn't advise ditching your knife in that situation, I'd advise rereading the 4S's thread.