» Planet Mike Puns
Covers monkey cloning, Gandhi, beer, and flunking English.
http://planetmike.com/jokes/puns/
» Pun of the Day
Archive of puns in categories such as food, transportation, families, education, and work. Plus a one-liner pun every week day.
http://www.punoftheday.com/
» PunLiners.com
Covers family, law, cows, mathematics and conmen. Offers a free newsletter and links.
http://www.punliners.com/
» Punpunpun.com
Has information about the annual O. Henry Punoff in Austin, Texas, Punster of the Year awards, links, and bookshelf. Accepts contributions.
http://www.punpunpun.com/
» Puns Galore
A searchable database of puns collected from the internet.
http://www.punsgalore.com
» Puns for the ESL/EFL Classroom
Designed to help teachers of English as a Second Language. Also covers misuse of English. Requests submissions.
http://iteslj.org/c/jokes-puns.html
» Shaggy Pun Test
Involves taking a test about 100+ corruptions of phrases. Submissions are accepted.
http://www.extremelysmart.com/humor/puntest.php
» Steve Brooks Puns
The six-time winner of the O. Henry Pun-off World Championship offers "Inhale to the Chief", "Tex-Mexexistentialism" and "Lincoln's Texasburg Address".