How do I travel by cargo ship without being an employee?

I read that if someone cannot afford airline travel to another country, they could pay to go on a cargoship heading to that country for less or even help unload the cargo at the end of the voyage as payback for being taken on board.How do I travel by cargo ship without being an employee?
That may have been the case at one time, but it appears to be highly unlikely nowadays. Here's a site that provides some good info on the subject. Note what they say about working off your passage:


http://studenttravel.about.com/od/boarda鈥?/a>