attoparsec:
n. About an inch. `atto-' is the standard SI prefix for multiplication by 10^(-18). A parsec (parallax-second) is 3.26 light-years; an attoparsec is thus 3.26 * 10^(-18) light years, or about 3.1 cm (thus, 1 attoparsec/microfortnight equals about 1 inch/sec). This unit is reported to be in use (though probably not very seriously) among hackers in the U.K.

(http://developer.syndetic.org/query_jargon.pl?term=a...)

Pi seconds is a nanocentury.

10^12 microphones = 1 megaphone
10^12 pins = 1 terrapin
10^21 piccolos = 1 gigolo
10 rations = 1 decoration
10 millipedes = 1 centipede
1 centipede/second = 1 velocipede
3+1/3 tridents = 1 decadent
10^6 bicycles = 2 megacycles
10^7 micrometers = 2 pentameters
10 monologues = 5 dialogues
5 x 10^2 millenaries = 1 seminary
2 x 10^3 millenaries = 1 binary
10^(-5) dollars = 1 Milicent
1 milli-Helen = beauty required to launch one ship
nano-nano = a prefix designating 10^18
0.3 decals = 1 trial
5 grams = 1 pentagram
5 monocles = 1 pentacle
10 decimates = 1 mate
10 milliners = 1 centner
10 embers = 1 December
10 dents = 1 decadent
100 decides = 1 decade
3.0410 x 10^6 microbes = 1 tribe
0.5410 x 10^12 bibles = 1 terrible