Wikipedia helpfully explains:
The yobibit is a multiple of the bit, a unit of digital information
storage, prefixed by the
standards-based multiplier yobi
(symbol Yi), a binary prefix meaning
2^80. The unit symbol of the yobibit is Yibit or Yib.1[2] 1 yobibit = 2^80
bits = 1208925819614629174706176 bits =
1024 zebibits[3] The zebi and yobi
prefixes were originally not part of
the system of binary prefixes, but
were added by the International
Electrotechnical Commission in August
2005.[4]
Now, what in the world actually takes up 1,208,925,819,614,629,174,706,176 bits? The information content of the known universe? I guess this is forward thinking -- maybe astrophyics or nanotech, or even DNA analysis really will require these orders of magnitude.
How far off do you think all this is? Are these really meaningful units?