AS8758 IPv6 Tunnel Broker: IPv6 tunnel broker for switzerland.
BTexact Tunnel Broker: BTexact free IPv6 Tunnel Broker Service, provides DHCP automatic tunnels and reverse delegation facility.
Hurricane Electric, Free IPv6 Tunnel Broker: Online Registration System. [6bone, USA]
Public 6to4 relay routers: Nick's list of public 6to4 relay routers.
Singnet IPv6 Tunnel Broker: Tunnel Broker with NAT and IPsec option.