on simple note , i can tell u that whenver we create any clustered index on any table . the table will be moved to filegroup mentioned with that index
for example
create clustered index idx on table (column_name ) on fg1
now above index will move the table to fg1 filegroup.
but be careful while u doing this operation on production or with heavy table. it can cost u for haavy log
-------Bhuvnesh----------
I work only to learn Sql Server...though my company pays me for getting their stuff done;-)