Best free anonymizers
The best way to surf anonymously
My top pick here has long been Xerobank (aka TorPark), a special version of the Firefox browser that comes pre-configured to make use of the Tor anonymizing network. Now having looked at Opera Tor [1], suggested by subscribers Rob Fuller and Allan Marillier, I'm not so sure.
As you might have guessed Opera Tor is a special version of the Opera 9.21 Browser configured to use Tor. It's got some good things going for it. It's portable, it's smaller than Xerobank, it loads faster, it connects faster to the Tor Network and seems to run a little zippier as well. The Opera browser used as a base is more than a match for Firefox, with many features (including BitTorrent) built into the basic browser; features that need to be added as extensions to Firefox. On top of that you get the excellent free mail client that comes with Opera.
And it has another feature not available in Xerobank: the excellent Privoxy proxy server that provides powerful ad filtering, security screening and more.
So with all of these pluses am I making Opera Tor my top recommendation?
I would, except for a strange message that appears on eSnips, one of the two Opera Tor official download sites. The message says "This file has been flagged by our users as inappropriate and is under review." I have no idea what this means and my attempts to have eSnips clarify it have not been answered. What I can say is that Opera Tor has passed all the malware tests on my PC and is also rated 100% clean by Softpedia. A Google search also came up with a blank.
Draw your own conclusions, but Opera Tor is now the product I'm using on my personal USB flash drive. Freeware, all Windows versions 6.4MB.
[1] http://letwist.net/operator
Promising anonymizing network
I2P [1] is an initiative to provide a fully distributed and self organizing anonymous P2P network. I2P is designed to allow peers using I2P to communicate with each other anonymously — both sender and recipient are unidentifiable to each other as well as to third parties. It allows for anonymous web hosting within I2P and anonymous proxy access to sites outside I2P. It also supports BitTorrent file sharing. This is a complex product so I suggest you start with the noob's guide [2]. Also of interest is the web page [3] comparing various anonymizing systems such as Tor and Jap.
[1] http://www.i2p.net/
[2] http://forum.i2p.net/viewtopic.php?t=385
[3] http://www.i2p.net/how_networkcomparisons