Here, you can only import them if you have a permit from the police, for "collecting". Illegal to carry, and illegal to possess if you are under 21. Sure would be nice though . Same for balisongs. Should've bought a Benchmade model 42 when I had the chance...
Any number of normal locking blade knives can be opened instantly. They'll try to get you on owning a "gravity knife" in their near infinite zeal to retain the ability to prosecute anyone who can produce the scary "snap" of a knife opening, however, unless you're seen actually doing it, it's pretty easy to tension a quality folder that has an accessible pivot nut just right so you can whip it open as a gravity knife, but it's not painfully obvious it's one either.
If you're upset about the ability to collect switchblades and balisongs, I feel for you.
If you're moaning about the utility of not being able to have a switchblade/balisong for EDC, then I say it's no great loss. A properly tensioned lockblade knife that you can flick open is probably better. For instance, take my Emerson/Benchmade Super CQC7. (made back when they were still working together...) It's been my EDC blade going on 15 years now.
http://youtu.be/oLb06NuGFa4Apologies for the backdrop. I sit next to the "box storage cubicle" at work. I don't complain though, I'm the only employee in the company who dosen't have a management office who's got my own window, and it's very private back here. And no, the cut on my arm isn't from poor knife handling. I got that rescuing our new kitten from the top of the TV. I was only able to grab her one-handed and she didn't feel very secure, so dug in her claws.
It wouldn't be real good for the edge, but I could hammer the damn thing into the side of a cliff as a rock climbing piton or into a tree trunk as a foot-peg if I had to. Not many switchblades would survive that kind of abuse.