Zilla Anonimous surfer is an interesting application that lets you mask your IP address to prevent others from getting information about your online behavior, block advertisement and images from web sites you visit, and kill popup windows while surfing the web.
When you are connected to the internet, an IP address is assigned to your computer, and this information is available to your Internet Service Provider, and to servers on the web you connect with. This program acts as a proxy, and masks your IP information preventing others from tracking you down.
This program also has options to block images when online (to avoid adult content, publicity, etc.) and a popup killer that lets you surf the internet without opening those unwanted windows.
This program is free to download and use, but it comes with Relevant Knowledge, an application that analyzes and sends information about your browsing habits, so if you don't want to send that kind of information, you should not install this software.