How Does an Entrepreneur Protect His or Her Ideas for Launching a New Start-Up?

How do you protect your ideas for launching a new start-up?  The Silicon Valley IP Licensing Law Blog addressed this issue in the following blog post:

http://www.siliconvalleyiplicensinglaw.com/how-does-an-entrepreneur-protect-his-or-her-ideas-for-launching-a-new-start-up/