  urlLink Anil Dash has words of advice for people thinking of watching the New York marathon, although they are probably just as true for marathons run elsewhere. Amongst these words: Position yourself near the volunteers who staff the first-aid stations. Because they are Marathon Enthusiasts, they have boundless energy and endless interest in each runner who passes.
We spent three hours listening to one small woman shout "You're the best! You're a champion! You're doing great! We're so proud of you! " in an endless loop, at the top of her lungs, to each participant, no matter how pathetically demoralized and demolished they appeared or how poorly they were performing. After the race, make sure to seek the Enthusiast out, so she can specifically say, "I didn't mean you. You're a lazy slob. " 
