Last November, Google launched SearchWiki, which lets signed-in Google users to customize their search results. You can vote up results to have them appear at the top of your page or remove results altogether. You can also write notes on a given result.
Brian Ussery has noticed that Google may be testing SearchWiki Note sharing option being listed at the top of the SERPs. Here's an image he posted on Picasa:
Have you noticed this in your search results? Please share your findings in the comments below.