Headline Split Tester plugin by bhalliburton and peterbessman allows you to enter an alternate headline for every post on your blog. The headlines are then randomly alternated on your website until a certain number of “headline views” has been reached. At that point, a “winning” headline (as determined by the number of people that have clicked on each headline to date) is determined and that headline is shown going forward.
Download: http://wordpress.org/extend/plugins/headline-split-tester/
Headline Split Tester Plugin Review: http://weblogtoolscollection.com/archives/2010/11/23/plug-review-headline-split-tester/
