We noted that John Williams uses the C-Trumpet in his scores. One of the best references available on the C-Trumpet is from the Vienna Academy at the Vienna Symphonic Library web site.
Read. Learn. And hear demos under PLAYING TECHNIQUES.
The Vienna Academy is a great resource so be sure to bookmark it.

Reading the preliminary test results from other composers on the Kontakt 3.5 update beta that’s just been released suggests that the Mac Pro Nehalem is now the dominant music computer with the oft wished request of being able to do it all on one system, pretty much here.
The new 64-bit Kontakt 3.5, in standalone mode, [...]

This is the opening voicing in John Williams’ Liberty Fanfare (which you can download from iTunes): Trumpets - Trombones + French horns. The “formula” reads that the trumpets are doubled an octave below by Trombones and French horns. Musically, the D triad is in root position doubled down an octave. The top stave [...]

See why composer John Debney’s web site is so effective.

There’s a good reason you want 7200RPM drives in your laptop.