the Today show is doing a segment on "how it works" and this morning they spot lighted Big Ben.

Very interesting. I'm not a BIG clock guy, but the points I caught were:

Weights driving the clock are 3 tons.
3 clock makers work full time on the clock
they wind it 3 times a week.
there are 333 steps up the tower to the clock.

Ben was off 4/10 sec with GMT this morning.
The time is adjusted by placing old coins on the pendulum bob, which is quite massive. there were several stacks of coins on it, aka pokerplayer.com

Ben is 150 years old
Most think the name Big Ben refers to the tower, but it is actually the name of the bell (could they have meant the clock & bell).

Interesting segment.

Charlie,
here's some additional information.

* The bell "Big Ben" is 8 feet in diameter and weighs 13.5 Tons (British tons @ 2240 lbs./ton )

* The clock mechanism was designed by Edmund Beckett Denison.