Geography first. Here is an recent interactive map of unemployment, by county, nation wide. What you'll find is that in places where people outnumber cows and deer, unemployment is unacceptably high. In a swatch through the center of the country, running from North Texas, through Oklahoma, Kansas, Nebraska and the Dakotas - mostly "tractor country" per the map's float-over cursor - unemployment is quite low.
So - no, geographical displacement from the jobs does not seem to be a big factor.
What about a mismatch between skills and job opportunities? If that were the case, some sectors would have high unemployment while others would have very low unemployment, and many unfilled positions. Is that the case?
It's pretty hard to make a case for structural unemployment when the unemployment rate has doubled (or more) across a wide array of industries.
As Krugman puts it:
See the structural shift? Neither do I. As others have noted, basically unemployment doubled for every industry, every occupation, every state. Where are the sectors/occupations/regions gaining jobs? Nowhere to be found. There’s nothing structural about it.
(I grabbed the chart from Krugman's blog.)
2/16 UPDATE: Delong looks at the employment side.