This may seem counter-intuitive after forty-five minutes of futile hailing, but jumping in front of an oncoming bus is not the way to go. As each yellow cab passes in complete ignorance of your very existence, you may find yourself leaning over the curb further and further, edging into traffic step by step. Maybe if you're directly in the path of a taxi it will have to stop, you think, for the last time ever.
But you'd be wrong. Stopping in the middle of the road and causing instant gridlock isn't your job. It's the cabbie's, and he'll be offended that you're trying to steal his thunder. Treat a taxi like you would a subway train. You wouldn't wait for that on the third rail, would you?
Just be patient, and keep the preceding tips in mind. It may seem difficult at first, but eventually, after many years of dedicated training, you should be able to successfully flag down a cab. Then it'll be smooth sailing for the six blocks you needed to go. Unless you hail the dreaded, elusive Cash Cab. Then you just better make sure you've been boning up on your Ancient European History.