keybr.com is a nifty site that provides a flash-based on-screen keyboard to help improve typing skills.
The thing that I really like about keybr.com is how each key is color-coded to show how well you are typing that particular letter. The keys that need practice turn a darker shade of red, while the keys that are hit correctly are shaded green. Well worth a try to at the very least find the weaknesses in your typing style.
