The 'I'm Feeling Lucky' button is one of the two virtual buttons a user of the popular search engine Google can 'push' in order to submit her search terms to the Google search engine. (The other button is labeled 'Google Search').

The 'I'm Feeling Lucky' button, located just right-of-center under the search terms dialog box, redirects the browser to the page that Google's algorithms calculate to be the most relevant to the entered search terms. If instead the button on the left is clicked, (i.e., the 'Google Search' button), a list of 10 web page names and URL's , with a few lines excerpted from each, will appear under a Google masthead. Additional sets of 10 URL's, (in descending order of the relevance as calculated by Google's software), can be obtained as well, until all relevant pages have been viewed.

The practical value of the 'I'm Feeling Lucky' button is not readily clear, since it saves very little time while introducing the possibility of being redirected to an undesired page. (Furthermore, points out Jurph, one can easily accomplish the same thing without removing her hands from the keyboard, by pressing 'TAB-TAB-ENTER').

It turns out that the 'I'm Feeling Lucky' button is probably a relic of the Internet's earlier days, when bandwidth was even more precious, and page loads took much longer. DejaMorgana points out (via PM), that:

Once upon a time, saving one page load could save a substantial amount of time. And since many web designers didn't understand the art of supplying page descriptions, one could be completely flummoxed by the list of Google results even when they included the exact site one was looking for. [The 'I'm Feeling Lucky' button] simply got you there . . . It was an impressive display of search technology, having been implemented long before most other search engines could give you anything close to relevant results.

Impracticalities notwithstanding, the 'I'm Feeling Lucky' button is well known among Google users to be potentially entertaining. One famous exploitation of Google's page-ranking (and/or 'crawling') techniques is the Google bomb, which involves the use of the 'I'm Feeling Lucky' button. According to a December 7, 2003 report by the BBC, Adam Mathes is generally credited with inventing the practice of Google bombing in 2001. The result of a Google bombing campaign is that when a user enters a specific word or phrase into Google's search term box, and presses the 'I'm Feelink Lucky' button, she is delivered to a quite irrelevant page, usually with comic and/or political motivation. The most famous example of this is the 2003 Google bomb for the phrase "miserable failure", which gained national media attention. It still works as of today -- a user who enters the phrase "miserable failure" into Google's search term box, and then presses the 'I'm Feeling Lucky' button will be delivered to the official White House web site's bio for current U.S. President George W. Bush.

In Google's Spanish site, the 'I'm Feeling Lucky' button's equivalent is labeled as, 'Voy a tener suerte', meaning "I'm going to have luck" [my emphasis added] -- a subtle but notable difference, imparting a bit more optimism than its risk-taking English-language cousin.