Here are a bunch of links from
http://groups.yahoo.com/group/Volunteers-in-CH
that you could go through. Perhaps you will find something of interest near you...

A way to volunteer online
A UN sponsored program that puts people with IT, communications, research etc. skills in touch with charities that need those skills. You work by email/web. Might give opportunities for skilled expats in CH without German language.
http://www.onlinevolunteering.org

AIDS Hilfe Switzerland
http://www.aids.ch/d/index.php

ASHA for Education Zurich Chapter
an action group for basic education in India
http://www.asha-zurich.ch

Amnesty International in Switzerland
http://www.amnesty.ch

Benevol
volunteer opportunities - in German
http://www.freiwilligenjob.ch

Bergwald Projekt
http://www.silviva.ch/bildungswerkstatt/index.html

Blood Donating in Switzerland - Blutspende
http://www.blutspende.ch/de/home.htm

Caritas Switzerland
http://www.caritas.ch

Children in Need - Kinder in Not Switzerland
http://www.kinderinnot.ch

Forum Freiwilligenarbeit
info and links for Volunteer opportunities in CH
http://www.forum-freiwilligenarbeit.ch

Greenpeace Switzerland
http://www.greenpeace.ch/onlinewarrior/php/home_d.html

Kovive - Holidays for Needy Children in Switzerland
http://www.kovive.ch

Lifespark - Swiss based organization
Arranges pen-pals for people on death row.
http://www.lifespark.org

Mountain Wilderness Switzerland
Caring for nature
http://www.mountainwilderness.ch

Paidos - Helping Children in Geneva who are in Difficult Situations
http://www.paidos.org

SOS Kinderdorf Switzerland
http://www.sos-kinderdorf.ch

Schweizer Tafeln
coordinates food collections throughout CH
http://www.schweizer-tafeln.ch/de

Sport The Bridge
Swiss Charity Org for Street Children in Ethiopia
http://www.sportthebridge.ch

Stiftung für das kritisch kranke Kind
http://www.stiftung-chance.ch

Swiss Deaf Association
http://www.swissdeaf.ch

Swiss Homeless Soccer/Football League
http://www.in-kick.org

Swiss Red Cross
http://www.redcross.ch/e

Swiss Red Cross Kanton Zuerich
http://www.roteskreuzzuerich.ch

Swiss Sport for Disabled Association
http://www.plusport.ch

SwissSolidarity.org
fundraising site for disasters
http://www.swiss-solidarity.org

Terres des Hommes
http://www.tdh.ch/cms/index.php?id=391&L=1

The Swiss Federation of the Blind and Visually Impaired
http://www.sbv-fsa.ch

Tischlein Deck Dich
program to help feed the poor in CH
http://www.tischlein.ch

UNICEF Switzerland
http://www.unicef.ch

World Wildlife Fund Switzerland
http://www.wwf.ch