PubMedCentral

National Center for Biotechnology Information. A limited, but growing list of full-text sources.

FreeMedicalJournals.com

Selection of major impact journals in key fields. Some availability is delayed from one to six months.

Highwire Press

Stanford University Libraries. Major source of free articles on the Internet.

BiomedCentral

Peer-reviewed, open-access articles in medicine and biology.

FindArticles.com

Free article search service.