ErrorDocument 404 /
In the htaccess. Or spider the frick out of the site with Screaming Frog. There's an article on this;
http://www.seomoz.org/blog/8-ways-to-find-old-urls-after-a-failed-site-migration-whiteboard-friday
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ErrorDocument 404 /
In the htaccess. Or spider the frick out of the site with Screaming Frog. There's an article on this;
http://www.seomoz.org/blog/8-ways-to-find-old-urls-after-a-failed-site-migration-whiteboard-friday
Re-reading http://www.seomoz.org/blog/duplicate-content-in-a-post-panda-world
I don't think I have any choice except to use rel=canonical tags and work at improving page content. Adapting this question to ask the speculative "how much does duplicate content hurt my ranking"
There's a great htaccess file generator at http://www.htaccessredirect.net/