Author and investor Guy Kawasaki posted a poll today asking, “How much would you pay to use Twitter?” Surprisingly, about 50% said they would pay some amount, the majority thinking the service worth $5 per month. That idea seems so reprehensible to blogger Mike Arrington (probably one of the service’s heaviest users with over 30,000 followers), that he a quickly urged his thousands of blog readers to vote for the $0 option. (Which is why that 50% figure is rapidly declining.)