Seen this that I have just started using, I do get worried when typing in password etc on the web but this tool also creates a load of other letters when you type, it is a bit like the enigma machine. You can see it working as you type when your in a web browser (I use IE 8 so not sure what other browsers it works in)
It is nearly impossible to detect all keystroke logging software. Network Intercept's Free Anti keylogger Keystroke Interference is a solution that renders keystroke logging software useless. With chameleon-like characteristics, keystroke logging software can hide from even the toughest detection system. Network Intercept's Free Anti Keylogger Keystroke Interference solution protects against this existing threat whether it has been detected or not. The software inserts randomized characters into every keystroke to ensure that any information collected is completely muddled. In addition, artificial intelligence learns the user's natural typing pattern to further conceal the characters the user is typing. Logging software or someone monitoring a protected system will not be able to decipher the user's typing pattern or typed keys. This quick desktop-install program utilizes minimal system resources and will not slow down the user's computer. Free Anti Keylogger Keystroke Interference software download at CNET UK
I use every time I use my PC cause if you only use it when your going to login to your bank account for instance then any idiot will be able to figure out your password.