What I like about these contests is that while they are a way for a company to get exposure for itself and it's products, it also allows teachers to get exposure for the kind of great work they do.
Teachers work very hard to come up with creative and engaging lessons for their classes and they should be recognized for this. There is no reason for them to work in isolation any more. In this day of Web 2.0 and Social Networking, sharing your lessons and projects is easier than ever. Your efforts can help another teacher who has been struggling to come up with a lesson on that same topic. I'm all for sharing materials and lesson ideas across education.
However, I do believe that educators who want to use someone else's ideas should ask for permission or at the very least give credit. I have many labs and activities that I've either used directly or modified somewhat that I have gotten from another teacher. I've asked permission for any that I can contact the owner of and give credit for all of them. "Modified from a lab by ________ " will be on the page.
Many other companies have educator forums and sites like Adobe does and the whole point of these is to bring educators together and help them learn from and support each other.
Take a look at some of the great projects in the Adobe Educator's Choice Awards and submit your own ideas.
Other Educational Sites sponsored by companies:
HP - Teacher Experience Exchange