I have yet to deploy IPv6 in production, as I'm uncomfortable with offering a v6 product that is not up to the same standards as parallel v4 products. There are a number of companies offering IPv6 tunnel services, though. Below are two alternatives. You can pretty much google for IPv6 Tunnel Broker and find other vendors, commercial and free, that offer this service.

http://www.hexago.com/index.php?pgID=25
http://www.sixxs.net/pops/