So exactly how much is a trillion dollars?

With China and Japan both holding about a trillion dollars of US debt (with total foreign debt of 9T) I wondered, what exactly is a trillion dollars? How much does it buy?
Since economic power is so often linked to military power, I decided to calculate just how much military equipment one can buy with a trillion USD. So I found a nice table which lists the total number of all crew-operated military vehicles in US and for each type of vehicle I found the latest model and used its production cost to generously approximate average cost of a vehicle in that category. I then summed up the numbers, and here is what I came up with for all the weapons of the United States:

	# units	unit cost, mln $	total cost, mln $
Tanks	8000	3	24000
Aircraft carrier	21	4500	94500
Cruiser	22	1000	22000
Destroyer	52	1000	52000
Frigate	30	1000	30000
Corvette	46	300	13800
Nuclear sub	72	2000	144000
Fighter Aircraft	3200	43	137600
TOTAL			517900

I excluded traditional nuclear weapons here, because their cost is almost impossible to estimate correctly. Production cost is minimal and it is mostly the cost of installations, missiles and maintenance.

The conclusion is that a trillion dollar would basically buy the entire weaponry of the United States twice over.
Note also that the ballpark cost of the current financial crisis is already being estimated to be roughly 1 trillion dollars. Just to show how serious the crisis is - and it has only just started.