Most of the speed reading extensions listed in the comments use one word at a time. Maybe its just me but I find it very disconcerting since word lengths change causing a flashing experience. When I read I like the continuity of the sentence or phrase. Maybe in addition to selecting wpm there should also be an option of phrase length. I did an informal test and found that I could read faster than 400 wpm when reading the original text but found it tough to maintain context when using 300wpm using the bookmarklet