OT: Redirecting URL's / IP addresses for sites blocked by countries

I have recently seen a message from someone asking for help
in gaining access to an internet site that has been blocked
by a foreign country (not the Great FireWall of China but
the same idea).

Can anyone here tell me how to search for (or just point me to)
the software that allows you to set up an alternative domain name
or proxy to get around this type of blockade?
.