Here's an interesting excerpt from the new BBC series 'Supersized Earth' about big things. This clip shows the Boeing 747 Dreamlifter in action, unloading 787 assemblies, and also some good shots of 787 assembly.
Took a tour of the Boeing factory a couple years back, and it was most fascinating to see their big plane lineup strewn about the factory floor in kit form. It's a shockingly clean plant too.
If you find yourself in Seattle, it's definitely worth the drive up to Renton.