Am i required to fill out the 2006 American Community Survey I recieved in the mail ?

Answer 1

yes

Because it is part of the census, responding to the
American Community Survey is required by law. This
is analogous to the mandatory civic responsibility to
serve on a jury if called. The duty to
respond is set forth in Sections 141
and 193 of Title 13 of the United States
Code. This federal law also guarantees
confidentiality of the respondent’s
survey responses and imposes severe
penalties for a Census Bureau employee
who reveals individual data.