Never mind. I found an earlier posting by Tom Lane related to this issue.
---------- Forwarded message ----------
From: s anwar <sanwar(at)gmail(dot)com>
Date: Aug 16, 2007 10:48 AM
Subject: How to create a spatial index on point data.
To: pgsql-novice(at)postgresql(dot)org
How does once create a spatial index on point data. I did the
following and got the error given below.
create table foo(x point);
create index foo_x on foo using gist(x);
ERROR: data type point has no default operator class for access method "gist"
HINT: You must specify an operator class for the index or define a
default operator class for the data type.
Thanks.