Please send this on to Greg, I could not tell which email was his.  You guys are in for a trip to remember!
 
I went to Pamplona in 2001, it was a blast.  We were on a rapid trip through Europe, and just literally fell across Pamplona at the right time.  When asking what there was to do on a Friday night someone in Bilbao told us that we were in luck!  Jumped in the cars and went to Pamplona that night - drove most of the night.  We also went to the Tour de France that trip, it was not very far from Pamplona that year and we hit Wimbledon on the way home (not nearly as much fun!).  Pamplona is full of bands, fireworks and drinking wine all night and then lots of drunks running from the bulls in the morning. Right before the run everyone crowds the barrier's and starts climbing the buildings to try and get a view.  Saw one girl fall from ~ 30 feet up, sort of caught her, and she just started climbing the walls of the building again without even saying anything to me.  Be careful where you park, I (and 100s of others) got my car towed and had to pay $130 to get it back from impound - and there was not even a no parking sign.  I think the parking problems are a big income generator for the town.
 
If you run watch out on the streets, there are few if any porta-potties and the streets get very slick by morning!  The first night we got there we were walking down the first street headed to a concert and there was a ~50 year old guy taking a dump right in the middle of the street.  On weekends it is a party from noon till 9AM the next day, it can get so crowded that everyone starts playing pass the girl overhead.  After the run everyone looks for any open spot of grass to sleep the day away.  Not enough hotels for ~50% of the people that come on a weekends (including us).  Weekdays are little more subdued, and it is a little safer to run since you don't have as many drunks in your way. 
 
If they have not changed anything (it always takes the same route) along most of the course there are building walls or two ~ 8 foot wood walls on both sides, so once you decide to run there is no changing your mind at the last minute.  The run is narrow, I would say from 25' to an average width of ~15'.  It is nothing like the movies that Hollywood shows.  But this also means you can not turn down a side street or slip into an alley to get out of the way.  The walls are made so there is no way the bulls can get out into the watching crowds since there are so many people that no one would be able to move out of the way.
 
The most dangerous thing about running was all the drunks that could hardly walk yet alone run :).  It was easy (but scary) to get out of the way of the bulls, but the drunks are much more difficult to predict.  So most of the time you are just trying to figure out where you can go, and forget about the bulls till you hear them slipping and sliding behind you - they fall down a lot too- remember what I said about the streets!  Then if you are still alive and want more, you can follow them to the stadium and harass the bulls more.  They pen them up for 15 minutes to let them rest and get some energy back and then let them back out into the runners multiple times so everyone can watch the "fun".  If anyone else is going with you, this will probably be the only place they will be able to watch you on a weekend due to the massive crowds.
 
Locals will tell you that anyone that runs is nuts, unless they "know" the bulls.  Most Spanish think they are the only ones that "know" bulls, so Americans are crazy to even think about running.  Started to think it was like "knowing" sheep in Wyoming the way they talk about it!  Seriously there were several serious injuries every day we were there and one fatality.  I never saw any of them happen, with the number of people you can not see far at all.  But you could always hear the ambulance crews trying to get to injured runners and then trying to get back out of the narrow streets.  I did not feel that it was that dangerous, but that may have been the wine!
 
It is a great area, and if you get time try hard to go to San Sebastian and Bilbao ( you will probably fly into Bilbao).  San Sebastian is a great seaside town with awesome food and great bars that are open all night!  You can not even get into a restaurant till after 10PM in Spain, the Spanish like to stay up late even during the week!  We spent one night in SS going to bars then ended up in a shot bar till morning.  Then just before dawn we went swimming out into the bay - probably not one of my better ideas come to think of it the bulls were safer.  All the beaches are topless, a great place to go after a few nights in Pamplona to get some sleep on the beach!  but hard to sleep for long with the views.
 
Let me know how it goes and have an awesome trip!
 
John