Improve your touch typing
Why do all typing programs force you to type in line with the text you are copying? Either one mistake propagates and you can ruin an entire line by double typing some letter or the thing blocks until you hit the correct one.<p>Why is there not just a sample text and a simple text box that you type the entire sample into? Then your product can be diffed against the source and an accuracy rating calculated? This actually matches the normal typing experience.