Bingo- the 747SP is probably one of the most identifiable examples of 'in your face' area ruling. Look at this Pan Am one:
http://www.!!!!!!!!!!!!!!/open.file/347537/M/ That shaving under the fin is more than a nice big fat fin base (incidently the width of the base of the fin is 48"- not many people know that- or want to). This is where the wingtip area is running out and the fin/tailplane area is increasing, so to try and smooth out the profile slightly the fuselage has been shaved down. One of the favourite area ruling tricks is to vary the shape of a nice large wing-root fairing- Airbus A330/340 in particular:
http://www.!!!!!!!!!!!!!!/open.file/351871/M/ They're not really usable space as they are outside the pressurised body- they are just flimsy fibreglass structures braced with surprisingly weak looking brackets.