I still have great delight in handing back the small plastic-bag to the security agent after my carry-on etc has been through the scanner. They look completely confused, as if their brains are unable to work through a plan of action which is not a normal situation for them.
Once my liquids are in the bag, and in the tray, and going through the scanner, I walk through to the other side; there, I start to re-pack my carry-on bag. I remove my bottle of water from 'their plastic bag' and put the bottle into my carry-on. I hand the plastic bag back to the agent and tell them that I won't be needing it any more and would they like it back?
They usually tell me that I need the plastic bag for my my liquids, so I tell them it's not needed any more as my liquids are now in my carry-on bag, I don't want to litter their area and it's better for the environment. More confusion (for them). Next, they usually explain that it's for 'security reasons', so I ask them where the next security check is between me and the aircraft door, and whether they will have similar plastic bags there?
I've probably got various flags against my name in some database somewhere saying 'stroppy passenger'!