I think Jonathan mispoke. You cannot change the 'compare_with' attribute of an existing column family. The solution is to create a new column family with the data type that you need.
See 'help create column family;' -- Tyler Hobbs Software Engineer, DataStax <http://datastax.com/> Maintainer of the pycassa <http://github.com/pycassa/pycassa> Cassandra Python client library
