My younger brother did it during his European tour. Here's a quote of the actual running part, and a link to his journal entry describing the experience in the context of partying Pamplona -
I began a slow jog, allowing others to pass me by until the bulls were about a hundred yards back. I then sped up until I was running as fast as the crowd would allow. Hanging to the inside of the first turn, I risked crossing the road to be on the inside of the second. (the outside of the turn can be disastrous as inertia pulls the bulls in that direction)
Hazarding a glance back, I saw the first animal. It was a steer, not the sleek fighting bulls, but still horned and big and moving. What follows is a blur but I remember a flash of black and horn, a person falling and then diving through a fence.
Literally. Running full tilt I went between the fence slats and managed to stand in time to watch the last of the steer passing the second turn. I climbed back out in time to be caught behind the gate. I met up with Phil who agreed this was a stupid, stupid thing to do. Then the third rocket sounded.
Squeezing through at the head of the pack, I booked down the straight away. Behind me, a jangling of bells and hooves let me know I was losing ground. Sadly, just as the steer were passing me, my money belt snapped and snaked its way down my leg.
In a panic, I dove to the side and watched as the steer trotted past and into the stadium, the doors closing behind them.
Travelogue entry for
Running with the Bulls