A font that's only 2px tall, and somewhat readable! Uppercase and lowercase have some different variants, in case you find one more readable than the other. Numbers (sort of) and some punctuation marks are included.

You can probably read this, even if you wish you couldn't.
It tends to be easier to read at smaller sizes.

Try it out below, or download it (under CC BY-SA license, so you can use it commercially but you have to give credit).