Note a RTW fare is valid for 12 months so it is relatively easy to break your journey up and use mileage points earned on the RTW to come back to home.


eg.
RTW : LHR-LAX-MIA-JFK (using intercon and US trancon)
Points: JFK-LHR
3 months down the track
Points: LHR-JFK
RTW:JFK-HKG-DEL-HKG
Points: HKG-LHR
Another 3 months
Points : LHR-HKG
HKG-SYD-AKL-ADL-PER-SYD-LHR

(an example of an XONE4 from London with separate visitis to US, Asia and Australia. Could also tag some Euro flights onto the end of this)