i'm looking for some information here...how do you not be an "idea guy" if you have ideas? I have detailed business requirements, well thought out mockups, use cases, I listen well, "stay out of the kitchen", what else?
I'd say contribute in as many other capacities as possible, like sales, accounting, PR, business dev, etc. Make the final vision a shared one, and don't consider "the idea" to be what entitles you to the fruits of the business.