Databse Migrations using Rake without Rails

Database migrations can be a pain, it is for me anyway when I have to fire up an SQL window and execute commands (I'm lazy). Having used Ruby on Rails for a previous project I came across the command 'rake db:migrate' and loved how the creating of tables, columns and altering of those were reduced to Ruby code which is much easier to read and execute. I wanted to find a way to use that command on a project that wasn't using Rails. I found an excellent post on the subject, but I tweaked it slightly.