Sumo on the net:

Webpage Description
Nihon Sumo Kyokai
Kimrate Menu
Official Grand Sumo Home Page
Sumo Live
(Sumo Live old, not working anymore)
Live Sumo Video Stream
Sumo Reference (eng.)
Sumo Reference (jap.)
All numbers about sumo. About Sumo Reference "Your Sumo Information Archive"
Archiv of the Sumo Mailing List and addition Info
Sumo Infos in German
SumoForum Sumo Forum, Chat
Sumoforum German Sumo Forum, Chat
Sumo Information Tons of Sumo Data
Hakke yoi! Searchable database with sumo stats, banzuke and rikishi data.
--==[]==-- Bandey's Sumo Page
Sumo Movies Makuuchi
Sumo Movies Juryo & below
The Sumo Movies are provided for the personal, non-commercial use of fans unable to watch sumo in a timely manner by other means.
Sumo Movies on Info-Sumo French Sumo Forum
Sumo Colosseum CHIJANOFUJI'S Sumo Colosseum, Tons of Sumo Data and Infos Day by Day Basho-Reports
Kimarite Animated descriptions of Sumo Techniques
NSK Live 1 Sumo NSK Stream 1
mms://a1876.l12513457875.c125134.g.lm.akamaistream net/D/1876/125134/v0001/reflector:57875
NSK Live 2 Sumo NSK Stream 2
mms://a1366.l12513453365.c125134.g.lm.akamaistream net/D/1366/125134/v0001/reflector:53365
Kintamayama Moti Dichne's Sumo Site
First full Makushita Banzuke in english!