Geocaching.com

Includes large database on caches to hunt down, along with general information on geocaching.
http://www.geocaching.com/

Buxley's Geocaching Waypoint

Explanation of the sport, collection of recent news stories, maps of cache locations, a FAQ, and announcements of geocaching parties and events.
http://www.brillig.com/geocaching/

Degree Confluence Project

A project with the goal to visit each of the latitude and longitude integer degree intersections in the world, take pictures at each location, and post pictures and stories on the website. (Not exactly geocaching...)
http://www.confluence.org/

Geocache Rating System

Tool for helping geocachers rate the overall and terrain difficulty of their hidden caches.
http://www.clayjar.com/gcrs/

Geocaching Geocoins Canada

Geocoins are numbered geocaching coins that are designed to provide geocachers with a collectable, tradable and trackable cache prize.
http://www.geocoins.ca/

Navicache

Provides a wide range of information and listing resources for the geocaching enthusiast including worldwide cache listing service, forums, and chat.
http://www.navicache.com/

The Maryland Geocaching Society

Geocaching related resources related to caching activities in Maryland. Site includes forums, chat, cache listings and coming events
http://www.mdgps.net

Utah geocaching games

Variety of geocaching games in and around Utah.
http://www.cachunuts.com

Geocaching Australia

Australian geocaching portal complete with links to forums, mapping tools and personal cache pages.
http://geocaching.com.au

GeoSnapper - GPS Photography

Enables users to upload and distribute accurately geo-referenced digital photographs using a camera and a GPS receiver.
http://www.geosnapper.com

GeocacheUK

Information and resources for UK geocachers including forums, chat rooms, maps and stats.
http://www.geocacheuk.com/

Tampa Bay Geocaching

Resources for GPS enthusiats in the Tampa Bay, Florida.
http://www.tampabaygeocaching.com

Georgia Geocachers Association

Includes cache events in Georgia, what's new, issues facing the GGA, discussion boards, as well as a resource section.
http://www.ggaonline.org

North Texas Geocaching Association

Features news, articles, information on membership and activities, FAQs, links and contact details.
http://www.ntxga.org/

Wisconsin Geocaching Association

Dedicated to promoting the activity through out the state. Features message boards, links, maps, membership information and photos.
http://www.wi-geocaching.com/

St.. Louis Area Geocachers Association

Features information on the group, activities, discussion forum, links and contacts.
http://www.geostl.com/

Michigan Geocaching Organization

Promotes geocaching in Michigan. Site includes, forums, news, downloads, and articles.
http://mi-geocaching.org/

Geo-* - Linux tools for Geocaching

Provides free Linux software for the activity.
http://geo.rkkda.com

British Columbia Geocaching Association

Portal to caching in and around BC. Promotes geocaching in BC by providing the resources such as News, Events, Downloads, Links, Recent Caches, and Fourms.
http://www.bcgeocaching.com

The Groundspeak Forums

Includes discussions on general questions, geographical regions, adventures, and GPS related issues.
http://forums.groundspeak.com/GC/

Oklahoma Geocaching

News, forums and event listings for cachers in Oklahoma.
http://okgeocaching.com/

Colorado Geocaching Resource Pages

A summary of geocaching regulations in various Colorado public lands.
http://home.earthlink.net/~rsgeek

North Carolina Geocachers Association

Promotes and enhances geocaching throughout North Carolina. Listings of geocaches, information about membership and etiquette.
http://www.ncgeocachers.com

Ohio, Kentucky & Indiana Cachers

Serves as a forum for communication between area enthusiasts, the general public, and land management officials to promote the sport of geocaching. Includes forums, park policies and a discussion board. Located in Cincinnati, Ohio, United States.
http://www.okic.org/

Central Ohio Geocachers

Features a calendar of events, FAQs, forums and photos. Requires registration for full access.
http://www.cogeocaching.org/

Alabama Geocachers Association

Exists to allow enthusiasts to network with one another, to share ideas and experiences and to help share the sport of geocaching with others. Includes articles, downloads, events, forums, a journal, newsletters, photos and user registration/login.
http://www.alacache.com/

Geommunity

Dedicated to promoting and helping to build Geocaching communties through peer support and collective development of technical solutions. Includes downloads, FAQs, forums, archives and a members' list. Requires registration.
http://www.geommunity.net/

Geocacher University

Provides information about basic caches, equipment, events, resources, photos, items for sale and links.
http://www.geocacher-u.com/

Geocaching in West Virginia

Offers self-guided and rental trips. Includes general information about the sport, recommended equipment and other activities provided by Ace Adventure Center in Oak Hill.
http://www.geocaching-wv.com