http://www.ins.gov/graphics/lawenfor/specialreg/index.htm
INS Information on Special Registration

http://www.ins.gov/graphics/lawenfor/specialreg/Call_In_Group3.pdf
Group 3 - just added to special registration

http://www.ins.gov/graphics/publicaffairs/statements/ReminderState.htm
Deadline page

http://www.ins.gov/graphics/publicaffairs/statements/ReminderState.htm
Note from U.S. Department of Justice - Immigration and Naturalization Service
"INS Reminds Certain Temporary Foreign Visitors
of Eighteen Countries of Registration Requirement"

http://www.ins.gov/graphics/lawenfor/specialreg/CALL_IN_2.pdf
Group 2 

All of INS will be incorporated
into this new Department.
Immigration enforcement functions
will be part of the Border and Transportation Security Directorate (http://www.ins.gov/graphics/Title_IV.pdf),
and immigration services will be
housed in the Bureau of
Citizenship and Immigration
Services (http://www.ins.gov/graphics/Title_IV-E.pdf), which will report directly
to the Deputy Secretary for
Homeland Security.  Read more.