:data, upload help

Hi,

Im using the latest version of Rails and after reading Agile Web
Developments with Rails which uses version 1.2.6 im wondering how to use
the :data in a migration.

Im wanting to provide an upload for my end user to a database and in the
book it uses;

t.column :data, :binary, :limit => 1.megabyte

How can I get this working for the latest version?

Thanks!