On Sat, Mar 21, 2009 at 1:27 PM, Paul Skinner <[log in to unmask]> wrote:
>        Late to the party, but how was the fact that there are 42 zips
> crossing state lines determined?

From the Census data file posted way back in the second message.
http://www.census.gov/tiger/tms/gazetteer/zcta5.txt

42 was actually conservative, since I was only considering the
all-numeric ZIP codes.  A more general count reveals 54 overlapping
zips:

063HH CT NY
380HH AR KY
380HH AR TN
380HH KY TN
422XX KY TN
582HH MN ND
592HH MT ND
657HH AR MO
976HH CA OR
979HH ID OR
10004 NJ NY
37642 TN VA
38041 AR TN
38063 AR TN
38079 KY TN
38852 AL MS
42223 KY TN
51630 IA MO
51640 IA MO
52626 IA MO
52761 IA IL
55954 IA MN
56027 IA MN
56129 IA MN
56219 MN SD
57638 ND SD
59221 MT ND
65733 AR MO
65761 AR MO
67950 KS OK
69337 NE SD
71749 AR LA
72644 AR MO
73949 OK TX
79922 NM TX
82063 CO WY
82082 NE WY
83120 ID WY
84536 AZ UT
85534 AZ NM
86044 AZ UT
86504 AZ NM
86508 AZ NM
86514 AZ NM
86514 AZ UT
86514 NM UT
86515 AZ NM
87328 AZ NM
89439 CA NV
97635 CA OR
97910 ID OR
97913 ID OR
99128 ID WA
99362 OR WA


-- 
Mark J. Reed <[log in to unmask]>