Free Presentations in PowerPoint format

National Missing Children's Day Poster Contest - Entrants must be in 5th grade 

Free Contests For Kids

Poetry Contest, Essay Contest for Student Writers

Kids Sweeps from Kids Turn Central

Harper Collins Childrens Books 

Free Contests For Adults

Win a Trip for 2
 (US Airways, this one is occasional, 
but I keep an eye out since it includes air, hotel) 

From Lifetime TV - Fun & Game Sweeps

Sony Pictures
(These change with featured movies. Check in to see what they have currently)

Rachael Ray Show - All kinds of giveaways. Free to enter!

Pillsbury Bake Off Contest

Betty Crocker Store Sweepstakes - Win $250, quick entry online

Sweepstakes, Contests and Giveaways - Goodhousekeeping.com

Travel Channel Travel Bug Sweepstakes
(new contest every month, extremely easy to enter)

Contests and Giveaways compiled by Parenting.com 

Hallmark Channel
Occasional Sweeps with great prizes but often nothing is happening

Contests worth entering
(compiled by About.com - cars, trips, little stuff, big stuff!)