From the Washington Secretary of State website (and listed in the same order as there, which does not reflect any preference on *my* part):

Barack Obama / Joe Biden – Democratic Party Nominees
John McCain / Sarah Palin  – Republican Party Nominees
Ralph Nader / Matt Gonzalez – Independent Candidates
Gloria La Riva / Eugene Puryear – Socialism & Liberation Party Nominees
James E. Harris / Alyson Kennedy – Socialist Workers Party Nominees
Bob Barr / Wayne A. Root – Libertarian Party Nominees
Chuck Baldwin / Darrell L. Castle  – Constitution Party Nominees
Cynthia McKinney / Rosa Clemente – Green Party Nominees

Voter Participation in Presidential Election Campaigns
Those who wish to participate in the presidential election campaign process may contact the candidate or party of his or her choice for more information. Listed below are the political parties with candidates for president on the general election ballot.

Washington State Democratic Central Committee
615 Second Avenue, Ste 580
Seattle, WA 98194
(206) 583-0664
info@wa-democrats.org
www.wa-democrats.org

Washington State Republican Party
2840 Northup Way, Ste 140
Bellevue, WA 98004
(425) 460-0570
comments@wsrp.org
www.wsrp.org

Party for Socialism & Liberation
1122 E Pike #1289
Seattle, WA 98122
(206) 367-3820
seattle@votepsl.org
pslweb.org

Socialist Workers Party
5418 Rainier Avenue S
Seattle, WA 98118
(206) 323-1755
seattleswp@speakeasy.net
themilitant.com

Libertarian Party of Washington State
10522 Lake City Way NE, Ste C103
Seattle, WA 98125
(206) 571-1946
officemanager@lpwa.org
www.lpwa.org/voter

Constitution Party of Washington
10605 SE 240th Street, PMB 135
Kent, WA 98031
(253) 854-6524
contactus@constitutionpartyofwa.com
www.constitutionpartyofwa.com

Green Party of Washington State
GPoWS State Office
PO Box 70515
Seattle, WA 98127
(360) 875-0205 or (206) 781-3848
wagreens@gmail.com
www.wagreens.us