As we prepare to ring in a new year, RadarOnline.com takes a look back at the celebrities we lost in 2011 who made their memorable mark on the world.

Apple founder Steve Jobs died at 56 on October 5 after a long battle with pancreatic cancer. The tech guru leaves a vast legacy in his industry over the better part of four decades, listed as the inventor of household items such as iPod, iPhone and iPad, among others. He was also the driving force behind companies like Pixar and Atari.

Legendary newsman Andy Rooney died November 4, just weeks after his 1097th and final weekly segment on the CBS stalwart 60 Minutes, capping off a 33-year run.

PHOTOS: Celebrities We Lost In 2011

The comedy world remains in mourning for beloved funnyman Patrice O'Neal, who died at 41 in a New York hospital Monday after suffering a stroke October 19.

Among the tweets from O'Neal's peers following news of his death Tuesday:

Jim Norton: "I couldn't possibly love a friend more than I love you. Goodbye brother."

Sarah Silverman: "RIP Patrice O'Neal. You made us laugh til we cried."

Jay Mohr: "Just heard. Goodnight brother. Damn. Just ridiculous. Terrible. Beyond sad."