A decade of experiments with participation of nearly 700 children and young people in neighbourhood improvement indicate that young people are sharp analysts of and producers of ideas for their settings, but the gatekeepers of local development are reluctant to expand their top-down, expert-based mode of urban planning to include new groups. The aim of the paper is to discuss the opportunities and constraints of internet-assisted urban planning with young people in the light of three new experiments in Finland and to draw lessons for future development of internet-based collaborative planning.