Lots of our clients request Non-Compete Agreements for their employees. I generally try to talk them out of trying it, and if they insist, I refer them to their employment lawyer.
The reason I discourage Non-Competes is that the courts change the covenants so frequently, there's no real way to have a solid template to develop one.
Now comes the latest California Supreme Court ruling, which has established a 'bright line' rule in the case of Edwards v. Arthur Andersen. The ruled on August 7 that California employers cannot enforce agreements limiting competition by former employees, except within very narrow statutory exceptions.
If you really believe you need a Non-Compete Agreement for your employees, please consult your attorney. And read this excellent article from Cooley Godward & Kronish LLP.