Mixergy has some great suggestions on ideas for starting a new company.
Here are some other means to find ideas:
1. Keep a list of things that bother you or other people every day. This could be big or small – your commute, the way your brush works. Try and fix that problem
2. Brainstorm with friends on things that need to be fixed.
3. Review large company balance sheets (This is the follow the money approach). Then find out where they make money the most or where the spend money the most. Keep asking questions on how you can increase their revenue or reduce their cost.
Your turn. But remember to take a break once a while.