http://www.eco-imperialism.com/content/article.php3?id=89
http://www.junkscience.com/ddtfaq.html#ref4 pro DDT
http://www.ourstolenfuture.org/Myths/myths.htm
http://info-pollution.com/ddtban.htm anti DDT
Bug_Girl has written a lot about this on her blog: http://membracid.wordpress.com/
Bottom line: it shouldn't be banned, but neither is it a panacea or a cure-all. It can be part of an effective mosquito control policy, but you need lots of other stuff, too.