Well, that didn't take long. Earlier today, Blake Ross, Facebook's product director and co-founder of Firefox, and Facebook engineers Tom Occhino and Marshall Roch released a bookmarklet called "don't be evil" (a jab at Google's informal motto) that tweaks Google's newly launched Search plus Your World (SPYW) feature to surface results from all social networks, not just Google+. Computer Science student Andrew Guenther has released a Google Chrome extension based on the original script; you can download it yourself from Google's Chrome Web Store.
Here's the official description:
Modifies Google's hardcoded Google+ search results and replaces them with real social media results.
This extension is based off of the http://www.focusontheuser.com's bookmarklet which replaces Google's hardcoded Google+ search results with real social media results.
The original bookmarklet requires that you click on it after you submit your query to Google. The new results include links to CrunchBase (not exactly a social network, but okay), Facebook, Flickr, Foursquare, FriendFeed, GitHub, Google+, LinkedIn, MySpace, Quora, Stack Overflow, Tumblr, Twitter, instead of just Google+. Once you've visited google.com and clicked on the bookmarklet once, it will continue to work for subsequent queries until you click away from google.com. Next time you visit google.com, however, you have to click the bookmarklet again.
As such, these four paragraphs describing the bookmarklet are also accurate for the extension:
If Google's search engine decides that it's relevant to surface a Google+ page in response to a query where Google+ content is hardcoded, the tool searches Google for the name of the Google+ page and identifies the social profiles within the first ten pages of Google's search results (top 100 results). The ones Google ranks highest, regardless of what social network they are from, replace the previous results that would only be from Google+.
To be clear: the tool not only reorders the search engine results, but also the results of the promotional Google+ boxes on the right side of the results, as well as the autocomplete results that feature Google+ accounts when you type into the search box. In Google language these three are known as: People & Pages results, Google+ Sitelinks, and Google+ Suggestions In Autocomplete.
The bookmarklet even shows profile pictures, which are pulled directly from Google. The tool enters the address of the new social result into Google's Rich Snippets Testing Tool and uses the information that Google provides. In other words, Google is only showing images for Google+ results, even though it has images from many other services.
By the way, the tool might not work for you because SPYW hasn't been rolled out to everyone yet. Google has pushed out the new social features on google.com to a percentage of U.S. users. If you don't see any of the Google+ social results on Google yet, you do not have the feature yet, so you can't use the "don't be evil" tool.
Google says it requires permission from other social networks like Facebook and Twitter to deeply crawl their websites in order to provide a consistent experience with SPYW. Since Facebook and Twitter don't give Google permission to their users' private content, SPYW mainly features Google+ content, and neither social network is very pleased about this.
The point of the bookmarklet (and now extension) is to show Google is lying; the search giant already indexes all public information on social networks, and there's no reason why it can't use that data as well. The tool never accesses any server or API outside of google.com. The information being provided has already been indexed and ranked by Google.
The bookmarklet was originally released for Chrome, Firefox, and Safari (Internet Explorer and Opera users are out of luck), so it's still possible someone will build a Firefox add-on and/or a Safari extension. By the way, there already is a Google Chrome extension over at focusontheuser.org/extensions.php, but it hasn't made it to the Chrome Web Store. Furthermore, Guenther posted his code on GitHub, so you can see everything that he's done.