Content: create a video of yourself performing your favorite magic trick to illustrate the connection between science and magic. Max 2 min.
Deadline of video contest submission: June 9 2008
Eligibility: Adult (15 and older) and Kids (14 and younger) categories (of the USA?)
Prize: The title “Master Magician of the New York Hall of Science,” along with a Magic Prize Package including a $50 gift certificate to the Hall, will be awarded to the producer of the top video in both adult (15 and older) and kids (14 and younger) categories. The three top finalists in each category will receive New York Hall of Science t-shirts.
Rules of video contest: NYScience.org

Here’s Card Science as an example for the contest by Elizabeth Wade

Although War on War music video contest is linguistically based on a paradox with its motto - not that ‘peace on war’ would have sounded better, here we are in a language virus trap. But let’s just move on from the motto. The contest is based on Sam Harris’ song entitled War on War and the aim is “
to counter the GOP’s stance of “staying the course.”

Content: submit videos of War on War using the song and any free stuff that is made available to you.
Deadline of video contest submission: June 22 2008
Eligibility: anybody
Prize: mixture of cash and other good stuff, $3000 for the first, $1500 for the second and $700 for the third winner, in its total value.
Rules of video contest: SamHarris.com

Promo video for the for-peace video contest:

Quoting from Huffington Post

” The contest is open for anyone who wants to express their anger, passion and vision of a world without war by creating a video to my song. Resources for free video creation software, tools, video footage and royalty free photography from war documentarian, active duty Marine Jayel Aheram are provided at WarOnWar.INFO and additional contest information at SamTube.com. … We are supplying everything needed to create a music video, at no expense to the contestant: The song, royalty free photography, vintage and current event stock footage, and the software to put it all together. Of course the more inventive entries use their own footage and find other components., but basically, people don’t even need a video camera or equipment. We currently have entries ranging from a 16 (year old boy) to 60 (year old woman).”

“Calling all aspiring chefs ages 8-14! Here’s your chance to win a trip to New York City and be among the three finalists in a mango recipe cook-off at The Institute of Culinary Education. Grab your video camera and have a family member or a friend capture your skills in the kitchen as you whip up your favorite original mango recipe. The grand prize winner will get to cook alongside Simply Delicioso star Ingrid Hoffmann on television’s video magazine Health & Home Report.”

Content: submit videos of your mango recipe, creation, cooking art, or something edible mango dish
Deadline of video contest submission: from May 7 to July 7 2008
Eligibility: between 8 and 14 years old residents of the USA
Prize: There will be One (1) Grand Prize awarded. The Grand Prize consists solely of the opportunity for the Grand Prize Winner to appear on a television broadcast with National Mango Board spokesperson Ingrid Hoffmann; a trip for two to the final judging in New York City, N.Y., including round-trip coach air transportation for two between major airports in the United States nearest to winner’s residence and New York City, N.Y.; There will be Two (2) Runners-Up prizes awarded. Each Runners-Up Prize consists solely of a trip for two to the final judging in New York City, N.Y., including round-trip coach air transportation for two between major airports in the United States nearest to winner’s residence and New York City, N.Y.;
Rules of video contest: http://www.mango.org/risingstar/rules.php

Here’s a video on how you can cut a mango professionally:

Choose a surprising fact and make a video for the contest to give a chance to yourself to win $10,000 in the Mountain Dew Video Contest. Max 1 minute, plus include the logo or the image or both.
Content: submit videos of surprising facts
Deadline of video contest submission: from March 06 to June 05 2008
Eligibility: over 18 years old residents of the USA, “you must be a legal resident of the U.S. residing in one of the fifty (50) United States or the District of Columbia who is 18 years of age or older (19 in NE and AL)”
Prize: $10,000 is the grand prize
Rules of video contest: surprising facts TV

Post-it is used in thousands of ways, now you can show how you use yours in this Post-it Video Contest.

Content: submit videos of how you use post-it notes: “There are a million uses for Post-it® Notes and counting…such as: self-reminding, planning and brainstorming - to list just a few. But we also know that the uses for Post-it® Products are as unique as the people who love them! That’s why we want to know more - FROM YOU!”
Deadline of video contest submission: from May 1 2008 to Aug 18 2008
Eligibility: Submitting a video in this Contest is open only to persons who, as of date of entry are legal residents of Canada (excluding residents of the Province of Quebec) who are the age of majority in their province of residence and are registered users
of http://www.facebook.com.
Prize: First Prize $5000, Runner-Up $2500, Third Prize $1000
Rules of video contest: you can download the pdf video contest rules from the facebook profile of the post-it video contest here

For instance, here’s an office prank where you can fight a cubicle war with post it notes (the sound quality is really weak, but the idea is, hm, post-it):

Content: submit videos of Dockers commercials, max 30 sec.
Deadline of video contest submission: May 29 2008
Eligibility: over 18 years old residents of the USA
Prize: The Grand Prize winning Submission will be submitted for consideration to NBC as a commercial to be aired once during the June 13, 2008 broadcast of The Tonight Show with Jay Leno. Grand Prize has no cash value. Under no circumstances will the Grand Prize Winner be entitled to receive anything other than NBC’s consideration for air time.
Rules of video contest: NBC.com

Check out ongoing international and US video contests.

Dockers commercial, e.g.

Check out some more international and American video contests in the Video Contest Calendar.
Content: submit videos of your Thai holiday experiences max 3 min, 50 MB
Deadline of video contest submission: May 26 2008
Eligibility: the video contest is open to anyone around the world with any nationality.
Prize: three prizes worth a total of $5,000
Rules of video contest: http://www.tourismthailand.org/amazingcontest/

Here’s an inspirational travel video of Thailand to give you some ideas:

Content: submit videos of your S60 tips
Deadline of video contest submission: May 20 2008
Eligibility: members of youtube
Prize: The grand prize for both categories is one of the latest S60 devices and a Handango gift voucher, second prize is a Bluetooth headset and Handango gift voucher, and third prize is a Handango gift voucher. In addition, an S60 device will be drawn amongst all the submitted videos.
Rules of video contest: http://showyours60smarts.s60.com/

Content: Videos entered in the contest can address any animal rights issue, including factory farming, circus cruelty, animal experimentation, and many more. Max 3 min
Deadline of video contest submission: May 27 2008
Eligibility: sorry, I couldn’t find any specifications, please contact Pulin Modi 757-622-7382
Prize: The winner will receive a brand-new giant chicken costume–just like the one that PETA uses at KFC protests around the world–plus peta2 merchandise. And the winning video will be posted on peta2’s wildly popular blog.
Rules of video contest: on peta.org

Moby’s inspirational Disco Lies video: