Worried about keyloggers ? Frightened to use your credit card online ? KeyScrambler Personal will put your mind at rest. Admittedly the free version will only work with Internet Explorer, Flock & Fx but it provides another layer of protection in these security conscious times. It encrypts your keystrokes at the keyboard and when they enter your browser it decrypts them so you can see what you have typed but any keylogger waiting will only be able to 'view' the encrypted text.
Further protection for alternative browsers, e-mail, IM/VOIP etc.is available at a price if you are really paranoid. http://www.qfxsoftware.com/
This is a good security precaution, but Firefox users may* find that the latest version doesn't work well with that browser. The latest version approved on the Mozilla Add-ons site is v2.1.0.1. as shown here although you can download the latest version 2.5.0.0 here. It's called 'Experimental' as it hasn't yet passed Mozilla's testing procedure. It's probably worth trying the later version since you can always revert to the earlier one if any problems arise. Please note that you have to register to download an 'Experimental' Add-on. This is a separate registration from the one for the Firefox forums.
*'may' being the operative word here!
-------------------- "Power tends to corrupt, and absolute power corrupts absolutely." Lord Acton, 1887.