Travelled to Spain in July, 2004 for the running of the bulls. A group of seven of us, rented an apartment in Barcelona for a weeklong (Saturday to Saturday)stay. We then travelled by train to Pamplona for 2 nights. Even though it seems like we wasted money by having accommodations in both cities for the 2 nights, it was worth it to have an apartment in Barcelona. Some tips to consider in planning a Pamplona trip:
1) Plan way ahead-you need to reserve about a year in advance, to get good accommodations in Pamplona. We stayed at Apartmentos Mirrasierra-a real nice place.
2) Research the run. If you want to do it, you HAVE to be in the plaza in front of city hall(Plaza Consistoral) by 730am. They close the gates at that time, and clear the streets, so you'll be pushed out, and won't be able to run.
3) Know what you're getting into. During encierro, the streets of Pamplona are filled with pickpockets,drunks and some filthy people. Not to discourage you, just know what to expect.
4) If you go down during the run, STAY DOWN! You can be seriously hurt or killed.
5) Try to WATCH the run the 1st day you're there, so as to get an idea what you're in for. The run is as dangerous as you make it.
6) If you run into the bullring, look for a spot along the metal fence where you can hop out if you need to.

Toro!