What are CGI Proxies ?
It is a way to hide your IP address by communicating through a 3rd party server
A wants to talk to C but D is looking at him.
So to ensure D doesn't know A uses Proxy B.
Whatever A wants to tell C, he tells B to pass the message to C
so D will not know A is actually communicating with C.
I added a new gadget on this site for CGI Proxy Testing (To test if the Proxy actually hides your IP)
Here is a site containing CGI Proxy Locations.
If you still want to find more simply google CGI Proxy.
Some CGI Proxies are actually fake, meaning other then advertising they don't proxy your IP addresses.
So to test whether they work simply enter my blog URL and look at the gadget.
If it displays your ISP and Dynamic IP address assigned by your ISP, it is a fake proxy hence don't use it.