Actually, depending on conditions like age, gender and height, the limit can be way more than 511, probably around 10k or so, but I digress.

For me, I'd find a limitless text string useful in that I could properly colour my text. Usually you would need 7 pipes between characters, thus effectively reducing the string size from 128 to 16. With a larger size, this would no longer be a problem. Maybe such long strings could also be used to draw some sort of ASCII art.