There was an interesting article in last week's New Scientist on fonts. Essentially, the claim was made that having to read something in a more difficult font improved the retention of the material being read. A suggested reason was that:
When reading is easy, we skip the individual letters and instead turn the task over to the section of the brain devoted to pattern recognition. But when we trip over a word, it forces the brain to engage a different processing area: the dorsal parietal cortex, where the letter-by-letter reading mechanism is based.
So, there you are. Change the font on your eReader to Gothic and become a genius.