Every packet with wireless or wired is traced, record and analyzed.Now days its very hard to hide yourself from mens with "black hats".To cheat the system that you are from other country.Or simple to sent e-mail anonymous.Using proxy servers is not secured enough or you can't use services while you are behind proxy.I mean you can't use payment systems, because they simple found that you are behind a proxy server.
My review is for project "Tor".Tor is "gate" in english and is a network of virtual tunnels that allows people and groups to improve their privacy and security on the Internet.Like every program there are advantages and disadvantages.
Pluses:Its FREE, secured, change you ID with single click, and enough stable.
Minuses:There is a lot, aaa i mean for me.
I can change my ID(ip address) but it's completely unpredicted and it is change automatic at random interval of time.This is plus for developers but for me this is not.
Speed is between 16Kb/s and 24Kb/s not fast but enough.
Finally if you want to be invisible this is your application.You can run in on Windows or OS X and its come in package with other useful programs like privoxy.
Privoxy is a proxy server which blocks javascripts when you visit web sites.Java script are often use to detect you IP address.This is cool tool.AdSense code is blocked with privoxy and you can't use privoxy to generate invalid clicks :)
I'm always forgot something and probably will add it this week.
Links:
http://vidalia-project.net/ - complete package (tor,vidalia, privoxy).
http://www.torproject.org/ - tor project.
https://addons.mozilla.org/en-US/firefox/addon/2275 - tor button for firefox (with this addon you star firefox to use tor network.
Now is part for screenshots.