One of these free services is www.keybr.com, a fantastic site that offers practice sessions for people who want to improve their typing skills.
From the site:
"Have you ever wished for a way to practice typing so that you may become a more efficient and capable keyboard jockey? Typing at the "speed of thought," perhaps? Enter Keybr, the flash based type instructor you've been waiting for.Each time you go to Keybr, you will be presented with a couple of lines to type. The site will track your wpm speed as well as how many errors you make. Accessing the graphs that track your typing requires a free account with the site.
Keybr is very straight-forward. You can choose from three basic lessons that start with a certain number of keys on the keyboard, and then, as you progress through the lessons, more keys are added to the mix to make things a little tougher. As a nice touch, it keeps live track of all your mistakes and your words-per-minute (wpm), and even creates graphs of your performance."
Go check out the site and get typing!