http://aa5.2ch.net/test/read.cgi/nanmin/1130341652/465

# /_service/ は見せる
# KDDI を含むなら c-au
# DoCoMo を含むなら c-docomo
# それ以外は受け入れ

# Reroute other mobile phones
RewriteEngine On
RewriteBase /
# /_service/ (for getting LA)
RewriteCond %{REQUEST_URI} /_service/
RewriteRule ^(.*) $1 [L]
# au
RewriteCond %{HTTP_USER_AGENT} KDDI
RewriteRule ^(.*) http://c-au.2ch.net/$1 [L]
# DoCoMo
RewriteCond %{HTTP_USER_AGENT} DoCoMo
RewriteRule ^(.*) http://c-docomo.2ch.net/$1 [L]
# others are OK