Some of the most remarkable and memorable products, services, and movements have started with a common strand. Accidental innovation.
When the 37Signals team started BaseCamp, they weren't working on building a project management software product that would change the way that people think about web based project management. They were starting their own design business and needed a way to manage the projects that they were working on. The problem was, the project management software that existed did way too much. So they built their own. Now, they have a company that offers many products based on the platform that was born out of their own need.
Algae Venture Systems wanted to find a new way to grow and process algae because it was too expensive. Along the way, they found out some interesting things about what they were working on and how it could solve energy problems too.
Putting a ton of effort into planning the next great product is rarely useful. It is better instead to build something that scratches an itch that you have. Maybe someone else will have a need for what you have built too. Even if they don't, at least you will have something that meets your need.
Start building something. Maybe along the way, you will discover something that changes the scope and perceived limitations of today.