Just yesterday I used my Droid smart phone to check the weather before my ride; tracked my 27.83 mile ride (including elevation, average speed, total moving time, etc.); stopped to take a phone call from my wife; looked up and gave her directions for the cheapest place to get gas; found a restaurant and made dinner reservations (we're on a short vacation); and, found my way back to the hotel (yes, there was a short stretch where I wasn't sure where I was).
Like most tools, used properly, smart phones can be very helpful things.
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A conclusion is the place where you got tired of thinking. - S. Wright
Favorite rides in the stable: Indy Fab CJ Ti - Colnago MXL - S-Works Roubaix - Habanero Team Issue - Jamis Eclipse carbon/831