Have to agree with some of those above - a lack of consistency around the world, a lack of educating the masses and a lack of design of the security system that would help to speed up the process.
Some examples:
1. Last autumn flying through Tel Aviv, one of the most security conscious airports in the world. Had 2 x 100g choccie bars removed from luggage that then travelled in their own XL sized cardboard box.
2. Again Tel Aviv same time. Going through security questioning why the guy in front was putting a 2 litre bottle of Pepsi back in his hand carry - no liquids rule so OK!
3. Helsinki a couple of weeks ago. Passing through security, no inspection of boarding passes and ID, so any Tom, Dick or Harry non-traveling public could go air side for a wee bit of shopping or whatever and walk out through arrivals.
4. Copenhagen after security restaurants air side using metal eating irons handy for use on board.
5. Some airports, having at gate security meaning you get all those liquids (water, etc...) you purchased air side confiscated.
6. Be like the States, where they seem to have long, long tables before the x-ray machines, well supplied with trays so 2, 3 or more people can get themselves ready at at time.
Contrast to CPH where there is room for one. SLOOOOOW
7. Lack of signs explaining what's required - laptops in/out, belts, shoes.... Most places you have to watch to see what's happening up ahead to try and figure out what's required.
Contrast with CPH where they have displays and video showing what to do.
8. Have ushers helping passengers, telling people what to do, and controlling flow to multiple security lines - at least I won't end up always picking the line that's going the slowest.
9. and on and on.........