Hi there,

I have never been able to get a MetaFilter account, but here's an answer to
your US Voting Machines question from a student of political science
(myself)...

In the United States, many offices at multiple levels of government are
elected on the same date, at the same time and location.  This is usually
done on the same ballot (though the term "ballot" is used loosely, as it is
often large and multi-paged).  Of course multiple ballots may be used for
different positions, the real problem is that literally dozens of separate
elections are voted upon at once... President, Senate/Congress, State
Senate/Congress, County Judges, District Attorneys, County Controllers,
Mayors, City Councillors, and so forth... one estimate I encountered tallied
some 200,000 elected offices nationwide.

By contrast, elections in the UK (and my native Canada, as well) are held on
separate dates for separate levels.  Four our national elections, all we
need to do is vote for our local candidate in our riding... one slip of
paper with one X.  This is easy to sort, isn't succeptible to *too* many
errors of interpretation, and doesn't take too-too long thanks to our
relatively small voting populations.

Hope this helps,