Archive current page with Internet Archive's The Wayback Machine:

  javascript:void(open("https://web.archive.org/save/" + document.location))

Archive current page with archive.today:

  javascript:void(open("https://archive.ph/?run=1&url=" + encodeURIComponent(document.location)))

Search Google Cache for current page:

  javascript:void(open("https://webcache.googleusercontent.com/search?q=cache:" + document.location))

Open current Reddit post in Reveddit:

  javascript:void(open("https://www.reveddit.com/" + document.location.pathname))