I read from cnbeta a post which rounded up a few free VPN services. Some VPNs on the list are located in China, which basically renders these services useless to pass the Great Firewall of China.
Among the list of five VPN choices, I recommend to you a Sweden VPN service Relakks. After registering and supply some basic information, you can create a VPN link with the service address pptp.relakks.com, and surf the Internet very fast. Of course, you can choose from the list the ideal one for your needs. And if you know a better one, please share it in your comment.