What software can I use to superimpose 1 video file over another like in music videos?

I want to be able to create a video of myself running along a blue background and then superimpose myself in a video of eg deep space , so it looks like im running in deep space(the blue background would be replaced by the video of deep space)
The above is just an example of the things I would like to do

What PC application could I use to merge 2 video files in this way?

Please can an expert help me resolve this issue.
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

gpersandAuthor Commented:
Sorry, forgot to say I am using XPSP2
Irwin SantosComputer Integration SpecialistCommented:
Adobe Premiere
Irwin SantosComputer Integration SpecialistCommented:
You would use "alpha channel".. usually green or blue screen.. also known as "chroma key"
I like flash...
Another one is Seriouis Magic Ultra (http://www.seriousmagic.com/products/ultra/).

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Web Graphics Software

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.