Call KJR, KIRO, KOMO or any other station that has time available to talk about working towards a solution which keeps the team here.
Write and Email your local and state politicians and continue to let them know that this is an issue you care about. Remember when you get positive feedback to let the politician know that you appreciate it, if they don't see things your way let them know that this is a key issue for you and you'll be watching them closely.
Finally continue to write David Stern to let him know that we do want our Sonics in Seattle.
I will be updating this with Email addresses for those who may be of help.