The idea itself isn't the hard part. I come up with dozens of ideas every week. The hard part is turning that idea into a successful business. That takes lots of hard work, sleepless nights, pounding pavements, fruitless sales calls and emails, the list goes on. The old adage of finding a problem and solving it still applies. Just today, one problem that presented itself that a startup could solve is:

Employee Scheduling. My wife is a per diem float team nurse at the number 3 hospital in the United States. When she wants to work, she calls in to an automated phone system, and records a series of messages after the beep to schedule herself (day shift, 12 hours, department, name, phone number, etc). Someone then listens to all of these messages, as well as messages from department heads looking to fill staffing needs. This person in the staffing office then calls my wife at 4am to let her know where she should report (or if they don't have anything for her). Tell me why that can't be a simple online/mobile app, with Twilio integration to send a text message, voicemail, or email confirmation? The same app could be used to schedule appointments for nearly anything...dentists, hair salons, you name it. You could beef it up by offering options such as realtime availability, payment processing, etc., to make it applicable to multiple industries. And you could charge a monthly fee, or per appointment, you name it.

Of course to turn this into a startup, you'd have to build the backend, the app, and have a sales team to sign up businesses, but it could be a hit.