Don't wait for an idea. Start executing.
Alex Yumashev (founder of JitBit) in the Chasing Product podcast:
... They just sit there and wait for the idea to come.
I've met lot's of people that are saying: I'm doing Rails consulting and I'm just waiting for the right idea to come.
Don't sit and wait for an idea! It's about the execution. Even if you don't have an idea, you should start executing. ... Waiting for an idea is just an excuse for not doing anything.
Alex describes how he applies this mantra in his company:
We keep trying to launch a new product every 3 or 4 months. We have 7 or 8 successful products currently, but we have about 35 failures.
We tried launching so many things that no one ever wanted. And this is something that you should be ready for; building something that no one wants.
You should build a system that allows you to test and move on to the next product idea really fast.
A really smart approach, and a lot of really hard work.