I'd like to know what the weight of a million dollars in one hundred dollar
bills would be.  Also, what would it's approximate dimensions be if stacked?

Hello and thank you for your question.

According to the U.S. Treasury, "In $100 bills, the weight of $1
million is about 22 pounds." [that's 10 kg.]
http://www.ustreas.gov/press/releases/rr2748.htm

"The size of a dollar bill is 6.6294 cm wide, by 15.5956 cm long, and
0.010922 cm in thickness."
http://hypertextbook.com/facts/1999/DeneneWilliams.shtml

But a more accurate figure for thickness is the actual US government
requirement for currency paper
"Thickness (Caliper).  The thickness of the paper shall be 124 ± 7
micrometers when tested as specified in Section 4.2.3.5."
http://www.fedbizopps.gov/EPSData/TREAS/Synopses/142/BEP-06-0001/AttachmentASpecPCDT1-1TypeICurrencyPaper-17Aug05.doc
The same source puts the weight of the paper (without ink) or
"Grammage, grams per square meter" at 88.7 ± 4.0"

So, the area of a single bill is 6.6294 cm by 15.5956 cm which is
.066294 m  by .155956 m = 0.0103389471 square meters

Since $1,000,000 requires 10,000 bills, the total area of the bills is
103.389471 square meters
and the total thickness is 124 micrometers * 10,000 = 1,240,000
micrometers = 1.24 meters.
So the height of a single stack is 1.24 meters.
And the volume of the stack is 103.389471 * 0.000124 = 0.01282 cubic meters

And since the total area of the bills is 103.389471 square meters, at
a weight of 88.7 grams per meter or .0887 * 103.389471 = 9.17 kg
[add another .83 kg for the ink and you're back to the Treasury's 10kg. figure.

So in summary, you can have one stack of bills 1.24 meters = 48.82
inches high, or you can have, say, 4 stacks a little over a foot high,
22 pounds all together, or (if you prefer the metric system) 6 stacks
a little over 20 cm high, 10kg. all together.

Search terms used:
"dollar bill" length width cm
treasury  length width thickness site:.gov
and lots of Google arithmetic, for example
://www.google.com/search?sourceid=navclient&ie=UTF-8&rls=GGLD,GGLD:2004-08,GGLD:en&q=124+micrometers+in+inches

Thanks again for letting us help.
Google Answers Researcher
Richard-ga

Prompt and thorough.  Thanks much.

Here is information about a currency bill, According to the Bureau of Engraving:

* Our present sized currency measures 2.61 inches wide by 6.14 inches
long, and the thickness is .0043 inches.

* The approximate weight of a currency note, regardless of
denomination is (1) one gram.

$1,000,000 is 10,000 $100 bills, which weighs 10 kg or about 22
pounds. If stacked in one stack, the height would be 43 inches high or
about three and one half feet. Easy to carry in a briefcase if that is
what you had in mind.

... and just in case any Australian screenwriters need to know the
dimensions of Australian Dollars, the Reserve Bank have just been kind
enough to advise me via email that:

"$1 million would be equivalent to 10,000 $100 notes or 1 sub-pack.  The
following measurements (millimetres - length x height x thickness) are
for 1 sub-pack of $100 notes: 325 x 125 x 335.

Based on historical data, the average weight of 1,000 $100 notes is
approximately 1006 grams.  Therefore, the weight of 10,000 $100 notes is
approximately 10,060 grams or 10.06 kilograms."

(a kilogram weighs approx. 2.2 pounds)

(I like the sound of these sub-packs! I think I'll start collecting them.)