I believe the next terrorist attack on the U.S. will be somewhere on the West coast, involving some kind of huge truck bomb on a famous target. They don't have either bio or nuclear weapons available to them at this point.

This truck bomb (or God forbid, several truck bombs) was probably prepared months ago, long before all the FBI's sensitive antenna on explosives and such went up, and has only to be driven to a selected target, of which there are probably several alternates.

Since these guys are suicidal, they can just blow the bomb up while they're driving along past the target. The suspicious move of leaving the truck parked near the target, which would raise all kinds of flags, would never have to be done.

How many potential targets do not have a road nearby along which semi trucks (or lorries, for you Brits) do not routinely travel?

Corollary: potential out-of-the-way targets like nuclear plants and dams, where trucks do not usually go, or are routinely subjected to more stringent security, are safer than targets like city buildings near large public roads. Biggest targets: bridges, that actually are public roads. Anyway, large dams and nuclear containment shells would take one humongous explosion to make a dent in them, probably more than would fit on a truck using conventional explosives. Driving a 767 into the face of Hoover dam would do little more than leave a stain.

Here's hoping I'm wrong, or that the authorities are really on the ball.