The Public Patent Foundation
The Public Patent Foundation is a US-based non-profit. They fight bad patents and bad patent policy. They argue that software patents are particularly bad and they use the legal system to have bad patents overturned, surrendered or rejected.
The Public Patent Foundation (“PUBPAT”) is a not-for-profit legal services organization that represents the public's interests against the harms caused by the patent system, particularly the harms caused by wrongly issued patents and unsound patent policy. PUBPAT provides the general public and specific persons or entities otherwise deprived of access to the system governing patents with representation, education and advocacy.-- from PubPat web site.
You can support this excellent and important advocacy by donating money, or time as a legal or technical expert.