I was brain-dead on “Thursday”:http://blog.cfrq.net/chk/archives/2004/07/02/plumbing-trouble-and-bird-nests/. My neighbour helpfully pointed out that I can replace the cracked copper DWV piping with ABS; they make ABS < -> copper fittings for this purpose. No plumber required; even _I_ can work with ABS :-)
So I need to run out to the store and get a bunch of ABS piping, and adapters. However, I need to know what size to get. Applying my superior mathematics skills, I measure the outside diameter of the pipe at slightly less that 10″. Divide by pi, and the pipe diameter is slightly less than 3.18″. Now, I _know_ that copper pipe is made in 3″ and 3.5″ sizes, not 3.18″ :-). This could be an inside diameter vs. outside diameter thing, but the number is still strange. Still, it’s probably safe to assume 3″, right?
Fortunately, there is google. The third hit for “copper pipe diameter”:http://www.google.com/search?q=copper+pipe+diameter is “Notes on Pipe”:http://www.gizmology.net/pipe.htm, which explains that:
bq. Oddly, there is nothing about a ½” pipe that is ½”, be it copper, iron, or PVC
bq. Well, it seems that back in the beginning of time – copper pipe was introduced in the 1930’s – copper pipe was indeed standardized at the nominal diameter inside with a 1/16″ wall, making it 1/8″ bigger on the outside. As the metallurgy improved, allowing manufacturers to use thinner metal (and thus increase profits), they increased the inner diameter rather than decrease the outer diameter simply to allow the pipe fit existing fittings.
bq. As the manufacturers began to make bigger and bigger pipe, they found that 1/16″ wall thickness was insufficient. Thus, the inner diameter of larger pipes is smaller than the nominal size, while smaller pipes are larger.
And, usefully, a chart of nominal sizes with actual measurements, telling me that my assumption is correct; my 3.18″ pipe is, in fact, a 3″ copper pipe!
Next week, we learn why 2″x4″ lumber is neither 2″ nor 4″ :-)
Jeff K 
The dimensions and Energuide (about $3/year diff.) rating are slightly different. Also $1899-1599 = $300 and you get clear shelves, a wine bin and “ice in the door” and 1 less shelf for your $300. Anyway, the real answer is “don’t pay retail, they just want to catch you in a time of need”.
For just about anything big I buy now I present an ad from someone else and they either say “You should buy it there”, or “We can beat it by 10%”. I would start with Homeshow, Tasco and Goodmans(sp?) before I would venture to the Brick, Leons or Sears. Actually, they all have their niche, I guess (and in fact, Homeshow *is* the Brick… they just have a fantastically huge warehouse I like to poke around in). I’m starting to think Best Buy might be a good place to pop into as well. That said, I think I just don’t go to the local Brick, Leons or Sears because the ones near me are small, there’s a huge Leons in Whitby.
The dimensions are different because the curved doors are taller (they stick up above the main body of the fridge). I dunno why the Energuide numbers are different, but there was one side effect; the lower number (barely) qualifies us for a current government efficiency rebate of about $128.
We were in a hurry, and didn’t have time to shop around extensively. After looking at several online offerings, Sears had the best price/performance ratio for the stuff we wanted :-)