Why not use what they provide you to the max without cracking their security.
What you will need:
1. Access/login to a linux machine with ssh running on port 80 (or 443)
(See UnixShell - They're grrreat!)
2. The proxytunnel client program.
Creating the tunnel:
Firstly you will need to create a TCPIP tunnel through your proxy server. For my example I'm running OS X (on my shiny MacBook Pro).
To do this, add the following (2 lines) to your ~/.ssh/config file:
ProxyCommand /Users/teuton/bin/proxytunnel -N -p "local-proxy:8080" -u "proxy-user" -s "proxy-pass" -d "shell.my-host.com:443"
Great! We are all set! You may need to tweak these settings depending on your local proxy server type and configuration (NTML auth etc)
Now the easy part.
Creating the proxy:
To ssh into your machine simply type:
> ssh firstname.lastname@example.org
To make things easier it is advised that you create ssh public and private key pairs and set these up... (see ssh-keygen command, and always check access rights are correct!)
Now create a proxy to services you require.
The following will create a SOCKS5 proxy for you:
> ssh -N -D 8080 email@example.com
This will create a tunnel to your remote POP port: (local port 2110)
> ssh -N -L 2110:127.0.0.1:110 firstname.lastname@example.org
This will create a tunnel to a jabber port at a 3rd party host
> ssh -N -L 6222:jabber.third-party.com:5222 email@example.com
How all you need to do is create a script file:
~/bin$ cat t
ssh -N -L 2143:127.0.0.1:143 -D 8080 firstname.lastname@example.org
And you are set:
Lastly to configure your applications, just add a SOCKS server entry (no other HTTP/S entries should be added). Some applications may still not work. For these you may need to create custom direct proxies to specified ports.