For most LCD monitors turning on Clear Type makes the fonts look much smoother and easier to read. For some, however, it makes the font look awful. This is because Clear Type works by operating on the sub-pixel level. It tweaks the individual red, green and blue dots on the monitor to improve the resolution of the text. However, not all monitors are made the same and the positioning of those dots may make the text appear fuzzy round the edges as the text is rendered incorrectly for the monitor.
NOTE: This was rescued from the Google Cache. The original date was Monday 29th May, 2006.