Using a public proxy to login to services that require passwords is a big No No . A simple packet sniffer which is decoding all information passing through it would easily compromise the security of the account on which you are logging into.

Just provide the adequate security for your system and don't do anything stupid which people would hunt you for. I don't use a proxy, but there is a project called JAP, a program written in JAVA, which provides a free proxy server. This can be found here. There is an english version and a German one. But something I would promote more would be Proxomitron.

This is a program that protects your privacy, by not letting sites view the pages you've been on before etc.. It also helps you pass the Browser Privacy section at Symantec security check. It does not act as a proxy, so people still see your actual IP. But it is a safe way to minimalize the amount people can know about you through certain scripts. You can get this fantastic piece of freeware from Proxomitron.org .


Hope That Helps!
Matt