About.com: Letterboxing and Geocaching Attract Walkers
   Article describing the basics and the factors that motivate people to start letterboxing.
   http://walking.about.com/cs/walksamerica/a/letterboxing.htm

Aisling Dart
   Artist from Salem, Massachusetts describes her boxes.
   http://www.aisling.net/lb/MA/salem.htm

Atlas Quest Letterboxing
   Trip planning portal offers clue search by country as well as tutorials and premium members services.
   http://www.atlasquest.com/

Brett and Penny's Letterboxing Page
   List of their boxes planted, found, and exchanged, primarily in Oregon and the Pacific Northwest.
   http://home.agalis.net/bcostley/Letterbox/

British Columbia Letterboxes
   Introduction, photographs of personal stamps, and clues for boxes planted in southwest British Columbia.
   http://www.ajaster.com/letterboxing/

Buckaroo's Letterboxing
   Clues for boxes she planted in Washington and Massachusetts.
   http://sophia.smith.edu/~rlay/letterboxing.htm

Catbead Mischief
   Offering clues for letterboxes in the Syracuse, New York area.
   http://www.catbeadmischief.com/

Chowder's Southern California Letterboxes
   Search for boxes in Long Beach, San Bernardino and Lake Arrowhead, California.
   http://home.earthlink.net/~letterboxes

Chuck's Letterboxing
   Chuck and Molly's letterboxes in Connecticut.
   http://www.chuckstraub.com/Letterboxing/connecticut_letterboxes.htm

Dartmoor Letterboxes
   Introduction, tips and things to avoid, news, survey, and letterbox clues for the Dartmoor area.
   http://www.plympton.info/dartmoor/

Dartmoor Letterboxing
   Includes a forum, image gallery, map of the area, contact details, and the history of the activity.
   http://www.dartmoorletterboxing.org

First Finds
   Posts first finds submitted by new US letterboxers, organized by state.
   http://firstfinds.blogspot.com/

Fleur de Lis' Letterboxing Journal
   Weblog about his letterboxing hobby.
   http://fleurdelislb.blogspot.com/

Fox News: Letterboxing Makes Hiking an Adventure
   Feature story datelined Oakland, New Jersey.
   http://www.foxnews.com/story/0,2933,55367,00.html

Have Feet Will Travel
   Introduction, contact details, and guidelines for letterboxing in the Dartmoor area.
   http://easyweb.easynet.co.uk/~have.feet/boxing/boxing.html

History of Dartmoor Letterboxing
   Account first published as "More Dartmoor Letterboxes" by Anne Swinscow in 1986.
   http://dartmoorhistory.blogspot.com/

I-95 Letterboxes
   Clues to quick and easy letterboxes to find while traveling on Route I-95, from Maine to Florida.
   http://i95boxing.blogspot.com/

Letterboxers Anonymous
   Forum with clues and discussion topics. Includes helpful hints on methods and supplies.
   http://www.leecomputers.com/letterboxing/

Letterboxing Germany
   Clues for Germany and other European countries. Includes photos and tips. [English, German]
   http://www.letterboxing-germany.de/

Letterboxing Minnesota
   Includes letterboxing basics and clues for Minnesota letterboxes.
   http://www.littlekeylime.com/letterboxingmn.html

Letterboxing Questionnaire
   British university student studying letterboxing for her dissertation asks visitors to answer a few questions on the activity.
   http://homepage.ntlworld.com/chris.donovan10/

Mark and Sue Pepe
   Couple from Kensington, Connecticut describe activities in eleven states and the island of Aruba.
   http://markandsuepepe.blogspot.com/

Massachusetts Letterboxes
   Bonnie and Betsey Sennott offer clues to their boxes in Massachusetts.
   http://users.crocker.com/~bsennott/letterbox.html

NPR : Letterboxing
   Radio host Linda Wertheimer and Thomas Johnston, an enthusiast in Washington, D.C., find a letterbox near the White House. [audio]
   http://www.npr.org/templates/story/story.php?storyId=1832303

Nebraska Letterboxing
   Information about letterboxing in and around Nebraska. Includes clues and logs for local letterboxes, as well as some resources for letterboxing in general.
   http://www.letterboxingne.com/

NeeDeep's State Stamp Letterboxes
   Ambitious family project placing letterboxes in each state, patterned after the US quarters series.
   http://statestamp.blogspot.com/

New England Area Letterboxing Gatherings
   Mark & Sue's blog of letterboxing events in New England.
   http://gatherings.blogspot.com/

New Zealand Letterboxing
   Clues, views, and news including boxes from Team Psychokiwi, Judi, Linton, and the Bunny.
   http://www.psychokiwi.org/letterboxing/nzboxing.htm

Oklahoma City Letterboxes by Dennis Williams
   Clues to boxes in Oklahoma City as well as New Mexico, Alabama, and Costa Rica.
   http://david.snu.edu/~dwilliam/geog1113/okcboxes.htm

Perfect Circle Letterboxing Guild
   Family and friends offer clues to letterboxes in New Jersey and Pennsylvania.
   http://www.pcdx.com/pclg/index.htm

Silent Doug's Letterboxing Site
   Articles including getting started, outdoor ethics, and explanation of cryptic letterboxer codes. Also includes list of boxes found and clues for boxes placed in the northeastern region of the United States.
   http://www.letterboxing.info/

Stamp-in-the-Box
   A collection of information and clues relating to letterboxing, a hobby that combines hiking, art, orienteering and mystery in a treasure-hunt style activity.
   http://www.stampinthebox.com/

The Gazette: Letterboxing a Hobby of Inky Fingers and Hidden Treasures
   Article on local letterboxing from chain of community newspapers near Washington, DC.
   http://gazette.net/gazette_archive/2003/200328/damascus/news/167006-1.html

The Space Traveler
   Family offers clues for Pennsylvania, New York and other states.
   http://www.enter.net/~space/Pages/Letterboxchart.html

They Live and Breathe Letterboxing
   Abstract of an article by Chris Granstrom, with link to a few references.
   http://www.smithsonianmag.com/issues/1998/april/letterboxing.php

Urban Letterboxing
   Database of clues to letterboxes in urban locations, primarily in Europe.
   http://spacehijackers.co.uk/letterboxing/

Wanda and Pete's Letterboxes
   Clues for boxes placed primarily in Rhode Island, but a few in other states as well. Also includes logs of the movement of hitchhiker boxes, primarily in New England.
   http://alum.wpi.edu/~p_miner/Letterboxes.html

Washington Post: Thinking Inside the Box
   Article by Caroline Kettlewell describes her discovery of the activity.
   http://www.washingtonpost.com/ac2/wp-dyn?pagename=article&node=&contentId=A55308-2002Jul11

What is Letterboxing?
   Michelle Spalding offers a history of letterboxing in England and the United States with bibliography.
   http://www.gigagraphica.com/Michelle/letrbox.html

Yahoo! Groups: Letterboxing Northeast
   Discussion group for the northeastern US.
   http://groups.yahoo.com/group/LbNE/

Yahoo! Groups: Letterboxing USA
   Discussion group for US letterboxers.
   http://groups.yahoo.com/group/letterbox-usa/