Washington State Sports Collectors Association
Sponsors an annual show in Seattle. Includes club meeting times, show information and dates, dealer profiles, and membership information.
http://www.wssca.net/

TennisCans.com
Vintage tennis ball can and container database. Includes message board, photos, manufacturers, guide to cleaning cans, age, history, and type.
http://www.tenniscans.com

The Olympic Collectors Commission
Features stamps, coins and memorabilia items in a virtual gallery, including items from 1896 Athens and forward to Sydney 2000. Also offers event list and related links.
http://www.collectors.olympic.org/

Footballbabes.com
Collector of football (soccer) uniform shirts has photos of his collection modeled by women. Also offers shirts for sale or exchange, and a message board.
http://www.footballbabes.com/