JS_Harris - 6:58 am on Aug 11, 2013 (gmt 0)
Better than robots.txt would be to use the robots meta tag with "noindex,follow" as attributes.
Actually it would be better to use the googlebot meta tag with "noindex" as attribute. Why? Because Bing and Yahoo send traffic to this type of page still, only Google seemingly hates them, and robots would block them all. Follow is the default behavior so it doesn't need to be identified.
I have pages that Google has cut off 100% that are all-stars in Bing, I use the googlebot noindex meta tag on these with good results.