jim! how utterly great!
whow -- how did it happen? did you express interest in being hired (like being on an agent's list, or something), or did they simply remember you from that last film?
what's your scene about? what did /do you have to do / say?
i had my forst movie-experience as well just last month. not quite hollywood, though, but a feature film with a well-known german director, at least.
my part was to play a severe nordic walking instructor, explaining the technique and to give those two actors who played gossipping and scheming ladies a wigging (or several), both verbally and physically (had to push one of them into a cow pat).
it was such a great and intense experience, and i can totaly understand the buzzing and the high-wiredness you#re feeling, ebcause i felt the same.
the shooting of the three scenes i was playing in (with a total of less than 5 minutes) took 12 hours, and after that i was totally exhausted and absolutely high-strung and energized at the same time.
what a day, indeed, and in reading about yours, i re-live mine!
congratulations to you -- and tell us more!!

discussing the next take

close-up on me

me doing the exercises for the 87th time (for continuity reasons) while there's a close-up on the other actors
edited to add: there are some more pics of the scene shooting at
http://www.flickr.com/photos/panta/page2/ and
http://www.flickr.com/photos/panta/page3/