Here's some shots of a friends compression fittings and radiator, 1/2" internal diameter as opposed to mine which is 3/8" ID. Supposedly, only 0.5 - 1deg difference using the slightly bigger 1/2" fittings and tubing.
There is also a 45deg angled compression fitting pictured, quite handy if you need to route the tubing different directions. If i'm not mistaken, mo swivel pa ni sya, which is nice.
Also in the pic is the 1/2" ID, 3/4" OD (outer diameter) Black Tygon tubing. These things are nice and thick and less prone to kinking.
He will have his nicely spec'ed i7 system up soon, full CPU GPU watercooled using 2 independent loops for each. Can't wait...