Alley Cat Allies (http://www.alleycat.org) - As the foremost expert on feral cats, Alley Cat Allies promotes nonlethal control for feral and stray cats with trap-neuter-return (TNR) programs that effectively reduce their population by sterilization - not euthanasia. Educate yourself about ferals, strays and TNR here.
Best Friends Animal Society (http://www.bestfriends.org) - Excellent feral cat resource page providing: 1) simple guide to caring for feral cats in your neighborhood; why TNR works; how to obtain low-cost surgeries; the TNR process; and ongoing care; 2) veterinarian-written brochure for other veterinarians providing all-purpose answers to basic questions about feral cats, TNR, spay, neuter and caring for ferals, and more.
Spay USA (http://www.spayusa.org) - Nationwide network and referral service for affordable spay/neuter services. Is a program of the Pet Savers Foundation.
The Pet Savers Foundation (http://www.petsavers.org) - Nonprofit founded in 1992 to solve a growing national tragedy: the needless suffering and death of homeless companion animals, primarily dogs and cats.
Adopt-A-Pet of Fargo/Moorhead (http://adoptapetfm.org/) - "Matching rescued pets with loving homes". Adopt-A-Pet is a local animal rescue organization run entirely by volunteers. They have no shelter and use foster homes for the animals until they are adopted. Adopt-A-Pet is not affiliated with any other animal rescue organizations in the area, do not receive funding from any and are 100 percent funded by donations. View pictures of animals waiting for homes on their site!