Great find Rob! We are so close...
One I use all the time when calculating scales:
1 degree of latitude = 69 miles (approx.) = 111 km (approx.)
Also, re: the metric system. Use the metric system all you want; I'll be sad the day the imperial system dies. Like your crazy uncle, it may not work as well but it sure has character. I like to design measurement systems for my conworld that have just as many irregularities and eccentricities.
-Rob
Heres one that doesn't pop up much... a rood.
http://en.wikipedia.org/wiki/Rood
B.T.W I use google now to do a lot of measurement math. I guess most of you know but you can "search" for items like "3 miles in meters" and it generates the answers.
Hah, but it doesn't do roods !!!
You know, Sid James would have loved your last post
He would (im having another of those dense moments it seems)
I came across the term from a puzzle so given that were into full on puzzle mode this month - have a go at it if you dare...
http://stuhasic.com/enigma/enigm023.htm
(See 7 across or 1 down !)
Oh and let me tell you this. a) Its a corker, and b) its bleedin difficult - its no namby pamby fill in the blanks sudoku type puzzle.
Here guys... try this little program... highly useful
Bryan Ray, visual effects artist
http://www.bryanray.name
For fantasy battlemaps:
1 "pace" = 5 feet
Since I wanted to depart from the "you enter a thirty-foot-by-thirty-foot" room descriptions, I decided to create a fairly equitable system where I just had to count map squares.
(A pace is the average distance the Sarat covered for his left foot to hit the ground twice while crossing a bridge in my campaign)
This also seems a lot more like it would be a guesstimate for characters. "You enter a room approximately six by five paces". It makes it easier to hide secret rooms in buildings. (If the players want to pull out their measuring-rope, they certainly can....)