Manipulating Google search results used to be something of a black art, and those who crossed the line from search engine optimization to gaming PageRank with link farms got the Google Death Penalty -- being axed from the index.

While deceptive efforts to move Web pages to the top of Google search results pages still run the risk of excommunication, Google appears to recognize that the order of its search results needn't be sacred. The company that made its fortune by turning democratic option, in the form of Web links, into votes for relevance is giving its users a more explicit way to vote on its search results.

Google Lab's Experimental Search page, which lets users opt in to one of several ongoing search enhancement tests, has given a limited number of visitors the option of adding, moving, and removing search results from the search results pages returned by their queries.

"This experiment lets you influence your search experience by adding, moving, and removing search results," Google explains on its Web site. "When you search for the same keywords again, you'll continue to see those changes. If you later want to revert your changes, you can undo any modifications you've made. Note that this is an experimental feature and may be available for only a few weeks."

The difference between this experiment and SEO manipulation is that the changes made through the test service are apparent only to the person who made the changes, not to everyone using Google.

Those participating in this limited trial see two new icons alongside their search results: an up-arrow and an "X." The up-arrow promotes a given search result to the top of the search results page in a manner reminiscent of Digg-style voting. The "X" hides a given search result so that it no longer appears for the chosen keyword(s).

There's also a link at the bottom of the search results page where new Web page URLs can be entered so that they'll appear when the chosen keyword(s) are used in the future. Search results added this way, or through an up-arrow vote, get marked with an orange asterisk to distinguish them from exclusively algorithmic search results.

As to whether Google weighs votes to affect its index as a whole, the company provides no information. However, it would be a phenomenal waste of collective intelligence to ignore the results if, for example, a large number of people consigned the same search result into oblivion for obvious inappropriateness or irrelevance.