Web / Proxy Anonymizers…

[retroborg]

Ciao,
I was wondering which are the best and most reliable Proxy Anonymizers, Anonymizer tools / software & solutions in generals, for one to completely cover his/her online tracks from their ISP, hide your IP, to be able to send / receive e-mails, browse sites like Facebook, download / upload files & surf the web 100% anonymously? (Preferably free)

Thanks in advance

[retroborg]

How exactly do I change / spoof my MAC to a legitimate MAC of a manufacturer other than my Wifi adapter's? Is there actually a list with all the legitimate MAC addresses for all manufacturers out there?

I was also told that there's always the danger of Java (different from Javascript) or other embedded applets which generally do not proxy (unless you use a VPN), so in the case of a web based anonymizer, there's the potential for leaking local information, so it's always good to disable them.

So I disabled “Scripting of Java applets” in the internet zone security settings, custom level, of IE8 in WinXP Pro & Win Vista Business (Security level for this zone: Medium-High), but there are also many Active X controls & plug-ins, .NET Framework, active scripting, filters and a bunch of other components that are enabled, but I’m not quite sure what each one does and weather I should disable them or not?
What other applets should I disable?
Should I just set the Security level for this zone to: "High" and disable everything?

Or Maybe Mozilla firefox would be the safest way to go as far as privacy is concerned?

Thanks in advance