Go

Board Game Go
Canadian woodworker Carol Dufour uses unusual woods to create unique boards and tables.
http://www.boardgamego.com

GoGamestore
Canadian site offering a range of equipment including Chinese bi-convex YunZi stones.
http://www.go-gamestore.com

Kiseido
US and Japanese store which sell books and equipment and also provides related news, information and maintains a game server.
http://www.kiseido.com/

Samarkand
US store offering a wide range of equipment, books, and software.
http://www.samarkand.net/

Slate and Shell
US publisher of English language books, also a small selection of playing equipment.
http://www.slateandshell.com

Yutopian Enterprises
US store selling books, software, equipment, and souvenirs.
http://www.yutopian.com/go