In addition to CEAS Overseas programs, you can also look into the following opportunities:
 

STANFORD AFFILIATED

Stanford – Peking University Language Program: The Stanford-Peking University program combines an intensive five-week language program at Stanford University with a four-week practicum in Chinese at Peking University in Beijing, China.
http://language.stanford.edu/courses/asianSummer/stanfordPekingOverview.html

Inter- University Program: Language study in Yokohama, Japan and Beijing, China.
http://ieas.berkeley.edu/iup/  (China)
http://stanford.edu/dept/IUC/ (Japan)

Bing Overseas Studies Program (BOSP): Overseas Studies Program has opportunities for students to study in Asia; these programs are located in Beijing, China and Kyoto, Japan.
http://osp.stanford.edu

Undergraduate Research Programs (URP): If you are interested in conducting research overseas, URP has information on grants and fellowships. http://www.stanford.edu/dept/undergrad/urp/

The Haas Center for Public Service: The Center offers international service opportunities and resources.
http://haas.stanford.edu/

Stanford in Government (SIG) Fellowships: Stanford in Government has fellowships in Asia.
http://www.stanford.edu/group/SIG/fellowships06/international/06int.html

Career Development Center (CDC): Resources for work, internship, and volunteer opportunities abroad.
http://cardinalcareers.stanford.edu/icareers/

Overseas Resource Center (ORC): Information on several overseas opportunities including internship, work, and study abroad programs.
http://www.stanford.edu/dept/icenter/orc/

Volunteers in Asia (VIA): VIA Stanford Programs unite Stanford and Asian University students through short-term, cross-cultural education programs. Programs vary in focus and include such topics as service-learning, healthcare, language, and social issues.
www.viaprograms.org

Asia Technology Initiative (ATI): A student-organized entrepreneurship program. It provides summer internship opportunities in China, Taiwan and India.

http://ati.stanford.edu

NON-STANFORD AFFILIATED

Freeman Asia: Information and financial assistance for study in Asia. Opportunities include China, Japan, Korea, Taiwan, and Hong Kong.
http://www.iie.org/programs/Freeman%2DASIA/

Institute of International Education (IIE): Funding and programs for language study, internships and research in East Asia:

http://www.iie.org

Natioanl Security Education Program (NSEP): Funding opportunity for U.S. undergraduate and graduate students.
http://www.iie.org/programs/nsep/default.htm

Critical Language Scholarships: Funding from the United States Department of State and the Council of American Overseas Research Centers (CAORC) for summer intensive language learning: Chinese and Korean.
http://www.clscholarship.org/home.php

The Asia Foundation: Internship opportunities in Asian affairs and Asian exchange programs.
http://www.asiafoundation.org/Exchanges/overview.html

China Scholarship Council (CSC): Study abroad, international exchange and scholarship programs.
http://www.csc.edu.cn/en/admin/readarticle.asp?articleid=538

Taipei Economic and Cultural Office (TECO): Educational exchange, scholarship, study and work opportunities in Taiwan.
http://www.sfmoe.org/e_default.htm

Nambu Foundation: Summer internship in business industry in Japan.
www.nambufound.com

Gilman International Scholarship Program: Offers grants for undergraduate students of limited financial means to pursue academic studies abroad.
http://www.iie.org/programs/gilman/overview/overview.html

The Blakemore Foundation: Offer fellowships for advanced Asian language study.
http://www.blakemorefoundation.org/

Bridging Scholarships: Offer scholarships for study in Japan.
http://www.colorado.edu/ealld/atj/Bridging/scholarships.html

Rotary International: Ambassadorial Scholarship is an international scholarship program for study abroad.
http://www.rotary.org/foundation/educational/amb_scho/index.html

Council Exchanges: Teach or study in China, Japan, Korea, and Taiwan.
http://ciee.org/study.aspx

WorldTeach: WorldTeach volunteers in the China program teach in secondary school-based English camps in Hunan Province.
www.worldteach.org/programs/china_summer.html

Global Volunteers: Volunteer to teach English and assist with community development projects in China.
www.globalvolunteers.org/1main/china/volunteer_in_china.htm

StudyAbroad: A good resource to find study, volunteer, or intern opportunities abroad.
www.studyabroad.com

AISEC: Internship opportunities in China, Japan, Korea, Taiwan, and Hong Kong.
http://us.aieseconline.net

International Cooperative Education (ICE): Work and internship opportunities in Japan and China.
www.icemenlo.com

IAESTE: International exchange, leadership training, global skill development, and technical education; opportunities in China and Japan.
 www.iaeunitedstates.org

I to I: Work, internship, and volunteer opportunities in China.
www.i-to-i.com

Alliances Abroad: Opportunities to teach English throughout China
www.alliancesabroad.com

Languages Abroad: Intensive language course opportunities in China, Japan, Korea, Hong Kong, and Taiwan.
www.languagesabroad.com

Cultural Homestay International: Work or teach in Asia.
http://www.chinet.org/wta/wheretogo-asia.html

Boston University Study Abroad and Internships:  Language study and internship programs in China or Japan.
www.bu.edu/abroad

Global Volunteer Network: Volunteer in rural or urban China.
www.volunteer.org.nz/china/

Action Without Borders: Extensive database with volunteer opportunities in Asia.
www.idealist.org

Cross Cultural Solutions: Volunteer program in China.
www.crossculturalsolutions.org

International Volunteer Programs Association: Volunteer opportunities in Asia.
www.volunteerinternational.org