Search activity for Ledger has skyrocketed 7,400 percent, sending him to number 11 in the Lycos 50 and prompting an increase in search interest for his former girlfriend, actress Michelle Williams, who jumped 2,400 percent in online activity.
Interest in Ledger's upcoming film, The Dark Knight, also moved up the search meter, gaining 1,700 percent.
Actress Mary Kate Olsen saw her search activity climb 71 percent following initial reports that Ledger was found dead in her New York apartment. The reports were later corrected.
Meanwhile, the unveiling of the MacBook Air has caused a surge in search activity for Apple, sending it to number 10 from number 17 last week.
Former president Bill Clinton enjoyed more search interest this week than his wife, presidential hopeful Hillary Clinton.
Search activity for Mr Clinton was up 1,400 percent, due in part to the media frenzy surrounding his wife's campaign trail.
And with the Super Bowl just around the corner, the New England Patriots are scoring extra points with web users, with searches up 183 percent.
Interest in the Patriots continues to be driven this week by the media circus covering quarterback Tom Brady, as rumours concerning the condition of his ankle dominate news reports on the practice field in Arizona.
If the Patriots win Super Bowl XLII, they will be the first team in NFL history to end the season with a perfect 19 and 0 record.