As with many people in my line of work, you get approached quite often by people with new ideas about applications. Typically it happens at a party or something similar:
"Hey, you do web stuff?"
"Yeah, I try."
"I have this idea for this iPhone app."
At this point, my brain immediately goes into autopilot and I begin nodding incessantly. It's not because people don't have good ideas. Quite often, I hear great, very novel ideas. But that's where my interest stops.
What am I supposed to do now? Code it for you? You don't know anything about design, software development, even business. You bring nothing to the table but a single idea. And now if I go ahead and try to turn it into something, you might expect some cut for all that work. Maybe 50% or even higher. Only for thinking. Or worse, if it is successful, you'll sue me for "taking" the idea.
I'm not interested in taking on a partner whose only talent is to think about things. Thinking is great for philosophers, economists and politicians, but it doesn't do anything in the practical land of the living. This world is controlled by doers.
I have ideas all the time. Every single day, I'll have an idea about a new web application or business platform. And then I'll let it simmer for a while. Ponder through the problems. Ninety-five percent of the time, there is simply no viability. There's some large hangup that I can't get through, usually some kind of technical hurdle. I need someone who is as well-rounded as I am whom I can bounce those ideas off of and can offer professional expertise on different approaches, for, say, indexing a large collection of data. Thinkers can't help in situations like this.
So, put simply, save the ideas for yourself. If you give them to me, I'll take them and turn them into money. If you're lucky, I'll cut you in for a "finder's fee".