I have always thought about soliciting ideas from friends about their problems with the current application they are using or frustration with certain products.This page on facebook has a lot of startup ideas.People share their frustrations and problems.The solution could be your startup.Take a look,you may stumble upon an interesting idea.You can decide to create your own page and ask your friends and their friends to post their problems and share ideas they think can scale to be a company.
Users Sharing ideas on Facebook.