We don't currently have a setting that allows you to block another member from viewing your profile. We understand the importance of this feature though, and want to let you know that it's on our product roadmap. While we don't have a specific release date to share with you at this time, you're welcome to follow us on Twitter at http://twitter.com/linkedin or check out the LinkedIn Blog at http://blog.linkedin.com for the latest notifications on site improvements. Both options are great ways to stay informed about new features here at LinkedIn.
Until this feature is released, here are some things you can do: