Finally, in response to their sledge hammer approach to bad links following the Google Penguin update Google now allows you to disavow links. I am glad Google has finally given webmasters this tool. I have a site in the treatment industry and there are rotten links pointing to it which I had nothing to do with them. They have hurt the site and nobody will respond to requests to remove the links. It will be very interesting to see what happens when I submit those links via this tool.
This video from Matt Cutts explains how to use the tool.