From the folks over at www.whiteknot.org:
The White Knot is the symbol for marriage equality. Wear it every day to show your support and to create conversation. Use it to tell someone today that equal rights are important to everyone. Share the White Knot and spread the word that all loving couples deserve the same legal rights, benefits, and respect that civil marriage bestows.
Visibility is the goal. See where White Knots are appearing.
Whether you are gay, straight, or otherwise, please show your support by wearing the Knot and telling people why you are wearing it. Wear your White Knot to work, to school, to your place of worship. Together, we will keep the topic at the top of people's minds and keep the conversation going.