Tonight my father-in-law called with a math problem for me. He built a water tank out of six-inch pipe to go on top of his horse trailer. This will be much more stable and wind-resistant than the 55 gallon barrel that he had been strapping up there. He was trying to figure out how many gallons of water it would hold. He has 396 inches of 6 inch pipe. I thought back to my geometry days and somehow remembered the formula for volume of a cylinder: pi(r*r)*h . pi9*396 = about 11196 cubic inches. Thank you, Mac OS calculator. I brought up the Dashboard widget for converting units of measure. Alas, it doesn't convert cubic inches to gallons. Then I remembered that Google added a conversion feature recently. I figured it was a long shot, but I typed in 11196 cubic inches in gallons in the Google search window. Brilliant! 48 gallons. I gave Joe the answer and he said that was about what he expected. Thanks, Google. But that's not all. I came back later to see if I could have done the whole thing in Google. I tried (3*3)pi * 396 cubic inches in gallons. Wow. Very impressive.