There's some really shitty articles on Cracked, and sometimes really great. Today there was a terrific one and this thread reminded me of it: http://www.cracked.com/blog/7-reasons-news-looks-worse-than-it-really-is/
When it comes to politics, religion and conspiracy theories, trying to convince somebody why they're wrong never works. It doesn't matter how wrong they are...THEY think they're right, and they'll also think that you're an asshole...which means your correct points will never get through to them. You're better off just posting what you'd like to say and never returning to the thread, hoping that at least one person gets something out of it...because reading peoples replies will just be infuriating and ruin your day. It's the exact reason why I hid 85% of my facebook friends from the newsfeed section. I was so sick and tired of reading peoples stupid political opinions...I had to just eliminate them completely from my view.
Show them the clip of that Loose change nonk losing his cool and saying stuff like "yeah we meant to put mistakes in there".
Also point out that Mayor Rudy was advised not to install an oil based heating system in the twin towers, that's why they burnt like they did (perhaps somebody should sue the guy, hmm?)
There is also a book called Voodoo Histories which debunk a whole lotta CTs which is fun to read, can't remember the author, but hey you can google it (unless you fear the bods at google are reading your emails and sticking their collective dicks in your summer punch).