4 links
Charity Choice
charitychoice.co.uk
Encyclopedia of British charitable organizations in 27 categories in a fully searchable database.
Charity Guide
charity-charities.org
Searchable database of United States nonprofits. Website also features donation guide, procedures by which organizations can be listed.
Charity Portal UK
charityportal.org.uk
Searchable directory of UK charities. Charities listed by type, discussion forum and donation by click.
CharityGuide.org
charityguide.org
Directory of editorially-reviewed volunteer opportunities, which are entirely flexible and immediately actionable. Also includes volunteer vacations.