Compare typefaces with each other
American Typewriter (left) compared to Rockwell
Yes, this site has been around for a year or so, but it is still handy if you want to compare how 2-3 typefaces appear on the screen: Typetester. Change the foreground and background colors, the size, spacing and so on and see how readable it is compared to the other typefaces. Use your own fonts or the ones available on the website.