These markings found in Australia are around 20,000 years old, even older markings have been discovered dating back almost 28,000 years and are believed to be among the worlds oldest rock art.

Barry Lewis/In Pictures/Corbis

• Sudoku solution - May 24, 2013
• Sudoku - May 24, 2013
• Crossword solution - May 24, 2013

elcome to The Week's "What Next?" contest, an invitation to test your powers of imagination with challenges inspired by current events.

Click here for the results of the previous contest: Apocalypse-proof homes

Last week's question: An archaeologist has discovered an aboriginal cave painting in the Australian outback that was created 28,000 years ago. We asked you what graffiti could have been found next to it.

RESULTS:

THE WINNER: Say NO to the wheel
Irma Vidaurri, Fort Worth, TX

SECOND PLACE: Only 9,492,798 shopping days until Christmas!
Ron Sartore, Poway, CA

THIRD PLACE: Repent now! The world will end in 27,999 BC

HONORABLE MENTIONS:

The beginning is near!
Kurt von Kampen, Seward, NE

I love Lucy
Bennett Tarleton, Nashville, TN

Chief of tribe no born in this country!
Barbara James, Bedford, MA

Save the Palorchestes. Eat more Dromornithidae.
Dennis Gittinger, Fair Oaks Ranch, TX

When spear outlawed, only outlaw have spear!
Mark Karnowski, Lindstrom, MN

Larry King was here.
Neal Connelly, Mahtomedi, MN

Kilroy will be here.
Jim Tripp, Menomonie, WI

Betty White rocks!
Dawn Lowery, Loveland, OH

Strom Thurmond for Senate
Barry Wolfe, Roanoke, VA

Fred loves Wilma
Glenn Shimizu, Claremont, CA

For a good time, didgeridoo Oogina
Gene Huntley, Elkhorn, WI

Vote for Org: He will lower your taxes and increase your benefits
Charles Hardersen, Bloomfield, CT

A dingosaurus ate my baby!
Paul Kim, Covington, LA

Save the sabertooth!
John C. Lefton, Medford, NJ

End the Ice Age now and stop global cooling!
Jeffrey Contompasis, Ashburn, VA

Your uncle is a monkey.
Martin Schnuit, Glen Burnie, MD

No shoes, no shirt – welcome!
Betty Wilson, Portland, OR

Raptors rule! Dragons drool!
Lillian Mullen, East Orange, NJ

Lascaux was here
James Scillieri, Wayne, NJ

Marked with my iChisel 4
Robert Skrob, Tallahassee, FL

Day 12: Paleo diet seems to be working
Lily Helpenstell, Corvallis, OR

Come worship our totem with us.
Kenneth R. Updegrove, Cedaredge, CO

Ask not at whom the Kookabura laughs. He laughs at thee.
Randall Butler, Ventura, CA

Will paint your hut for food
Dan Mackney, Wetumpka, AL

My other dinosaur is a T Rex
Steve Robinson, The Villages, FL 

Watch this space
Richard Rochna, Virginia Beach, VA

Cubs lose. Wait till next year!
Shirley Hanold, Tucson, AZ

It doesn't get much better than this!
Bob Setterberg, Portland, OR