Suggested exercise:<p>Predict and then create a histogram of the leading digits of the file sizes of the non-zero-length files on your computer.<p>[<i>SPOILER:</i> when I did this once I found sharp peaks around digits that weren't 1. You are likely to see this if you have a large number of files around a particular size, examples: a) whatever your digital camera typically produces; b) whatever size your software encodes a typical song into. These files violate the assumption that you are sampling sizes over a wide range of sizes. After excluding these files I observed Benford's law quite closely on the remainder.]