It’s impossible. My friends must think I am nuts. Pretty much every time I eat a meal with someone, we come up with a good half dozen ideas for web sites, whether they be web applications or hubs where data and people concentrate.
It’s so bad, that we have to pick between good ideas, and work hard to not get distracted with new ideas, or let any ideas we have invested time into lose focus.
Part of the trick to finding good ideas is to look at what people are doing on a national level, and start local yourself. Craigslist did this very thing, by launching in San Francisco, and slowly spreading to other cities.
The other reason it makes sense to start locally, is because people like to do business with people near them. With people they can actually meet with. And your end goal can be to begin with a local site and gain popularity with it in one place, and then roll out nationwide over time.
There are so many possibilities now with the Internet, and since anyone can be an expert online, today is the day to look for ideas.