This excerpt taken from the DVN DEF 14A filed Apr 24, 2009.
Why didnt I receive a Notice in the mail regarding the Internet availability of proxy materials?
We are providing certain stockholders, including those who have previously requested to receive paper copies of the proxy materials, with paper copies of the proxy materials instead of a Notice. If you would like to reduce the costs incurred by us in mailing proxy materials, you can consent to receive all future proxy materials electronically via email or the Internet. To sign up for electronic delivery, please follow the instructions provided in your proxy materials. When prompted, indicate that you agree to receive or access stockholder communications electronically in the future.