What do I have to do to create an ad network that works similar to eyewonder.com where an advertiser uploads an ad and it displays on a publishers page. Do I need to create some type of flash window that allows the video or ad to be displayed?

your question is a little vague, i checked the site and they have 4 different ad formats, perhaps you could expand a little. Or are you wanting to create a duplicate of eyewonder and offer their services?

I would like to duplicate what eyewonder does and offer similar services but expand on them. I would also want to add contextual advertising also. If you are not able to expand on everything that do or give me a general idea. One service that i am particularly intrigued about the custom ads and in-stream.