I have participated in 3 startup weekends. I never started a company with the projects that I worked on, but I never intended to start a company from a startup weekend project. The reason I go to startup weekends are to have fun and network with other like-minded individuals. The people that I met at the events have helped my business. I have seen some neat companies start from startup weekend like Zapier (called snapier at startup weekend), MedSocket, and Nudge.