Maybe depends how hard they try to block you. The one I know works for sure is openvpn using SSL. But you must use ssl/tls so that it appears to be HTTPS traffic. The default I think for openvpn is to use pptp which likely is blocked and is pain to get to work behind some routers.
The best way to do this is to run the openvpn directly on a router that can run the correct dd-wrt image. Otherwise you will have to use a PC which needs to be left on.
You other option is to try to use one of the many public proxy servers but they may block those also. You could try to set up your own proxy but I don't know free ones and this is generally limited to only web browsing many flash based things do not always work correctly