Iodine
iodine is a DNS tunnel that encapsulates IPv4 network traffic inside the DNS protocol.[1] This is useful in coffee shops and other public wifi places that use a captive portal but do not block DNS requests.
VTLUUG's DNS tunnel
VTLUUG runs a DNS tunnel on acidburn. Anyone may get an acidburn account and it is required to have an effective tunnel. In addition there is a password to restrict access to authorized members, just contact any officer to get the password.
Using the tunnel requires a TUN/TAP interface and the iodine package.
sudo iodine -f acidburn.vtluug.org iod.vtluug.org
Then enter the password on the prompt. This sets up a 10.69.0.1/16 tunneled network over DNS. From there ssh into 10.69.0.1, which is acidburn's address and set up a proxy.
ssh bobandrob@10.69.0.1 -D 8080
As long as the iodine connection was made this will allow you to tunnel your network traffic encrypted around the captive portal.