I installed unixODBC, freetds and ruby-odbc with homebrew but ruby-odbc still wanted to use iODBC. I stumbled upon this blog post (http://digitaljacob.riff.dk/2009/10/26/using-ruby-odbc-with-unixodbc-on-snow-leopard/) outlining a fix by removing i386 references. Here is the resulting homebrew formula. http://gist.github.com/328197
