Setting a local proxy through a remote machine
To set up a local proxy using some computer in another network (in my case, my office computer to accessing MathSciNet search and such), go to a console and
ssh -D 42 YourRemoteMachineName
And then set Firefox to use a proxy. In preferences, go to the Advanced Tab and select Connection Settings. Here you should select manual proxy configuration, in localhost with the same port number (42 in this example) as you used up before. Now you can browse as if you were browsing in YourRemoteMachineName. See the figure for more information.
Some Mac/Linux-related posts you may like: