If you know what this is a picture of, and where it was taken, you could win a prize in the CNET Picture of the Week challenge.

Update (Monday, 11:47 a.m. PDT): The answer to last week's Picture of the Week challenge--which 28 people got--is the U2 concert at the Rose Bowl in Pasadena, Calif., on October 25, 2009. The concert, part of the band's 360 tour, was said to be the largest ever at the Rose Bowl, and was also said by YouTube to be the largest live-streamed event in history. Thanks to all who played, and to everyone, please come back on Thursday for this week's challenge.

That sure is a lot of people, and those are some bright lights. But what is this And where did it take place If you know, you could win a prize in the CNET Road Trip Picture of the Week challenge.

If you have those answers, please e-mail them to me no later than 6 p.m. PDT Friday (to daniel--dot--terdiman--at--cnet--dot--com, and PLEASE include "Picture of the Week" in the subject line). I'll choose a winner at random from among everyone who sends in all three pieces of the correct answer. Please forgive me if you don't hear from me if you're not the winner. I get dozens of responses.

Also, I've turned off comments because some people would post the correct answers there. I hate to shut down discussion, but I want you to figure out the answer on your own.

One caveat: no individual can win more than two prizes.

Also, for everyone who played regularly during Road Trip 2010, please note that this is the eighth of the weekly Picture of the Week challenges. With Road Trip 2010 officially finished--and therefore no more new Road Trip pictures per se--the challenge is now taking place weekly, each Thursday, and the photos could come from anywhere, not just Road Trip 2010 locations, and might be related to stories I've written in the past. So, please have fun playing today, and then come back each Thursday.

For most of the summer, Geek Gestalt was on Road Trip 2010. After driving more than 18,000 miles in the Rocky Mountains, the Pacific Northwest, the Southwest and the Southeast over the last four years, I drove 5,266 miles this summer looking for the best in technology, science, military, nature, aviation and more throughout the American Northeast. You can follow me on Twitter at @GreeterDan and @RoadTrip and find the project on Facebook.