Sunday evening, MAD -- freedom baggie (make that bolsita libertad, although culturally it just doesn't translate; we don't measure freedom here by the bagful) out and 120 ml (4 ounce) saline solution in hand luggage.

Screeners catch and ask to see saline solution. I take it out and explain what it is.

"Do you need it?"

"Yes, because by the time I get to London, all the pharmacies will be closed and I need the solution to store my contacts tonight. I could squirt a bit in my eyes to show you what it is."

"Go ahead."

(Squirt. Squirt.)

"That's enough. Its supposed to be 100 ml, but go ahead."

LGW Tuesday 6 pm. Freedom baggie ("ye olde freedome baggye") out, saline solution in hand luggage.

Screener stops the moving belt. Calls over another screener. "You see?" he says. "That one's more than three ounces."

Second screener: "Yeah, right."

Turns belt back on, hand luggage comes through and off I go.

Moral of the story: Send the TSA to Europe or Israel for training. They might even catch something dangerous.