Two Schools of Thought to 404 Error Page Designs

There appear to be two schools of thought when it comes to 404 error page design. The first, as exemplified by Apple and BMI, present the 404 page as a standard page within the regular site template Apple 404 page Twitter 404 page I've always appreciated the creativity that can go into the design of the 'independent' style of 404 pages and I would love to use my sites' 404 pages as a sort of creative 'easter egg' for someone who has the misfortune to arrive on them. However, I've held back from doing so because I feel that error pages which fit within the overall site design are more user-friendly. They make it easier for the visitor to corre...