I have just installed a Yahoo Answers clone on a sub directory on one of my sites. Take a look, please submit a question or answer one to see how it functions for you. Here is the url http://answers.freeonlineguide.net
Wow. That is dangerously close to the real deal. I have never seen an "Answers" clone before so it is very intriguing. Overall I like it . If you have a promotions plan for it, you should do well with it. Good idea !
Very, very close to yahoo's site. The site seem to work well but I would tweek the colors, at least, so your site is unique. I would also play around with the logo. It may look better without the shadow. Good Luck