Here's a few interesting lonks to help you write a jaw-dropping 'for and against' essay...

http://www.eoilangreo.net/ana/ni2/writing/for_and_against.pdf
http://learnenglishteens.britishcouncil.org/skills/writing-skills-practice/and-against-essay
http://es.scribd.com/doc/60719740/Topics-for-For-Against-Essays
http://es.scribd.com/doc/12347970/For-and-Against-Topics-Alexander