Mark wrote:
A little bird told me that you can get bus trips that tour the city that
start and end at the airport
If so this would be great as we have 6 hrs to kill whilst changing planes

6 hours in Singapore is pleanty of time to get out of the airport, either
on one of the official (free!) tours, or just on your own. The fast
and very efficient MRT (aka the train) will take you from the airport
to a number of down-town areas in 15-30 mins (depending on where you go)

www.changi.airport.com.sg will have most of the details you need, or
search the web - there's no shortage of information on Changi Airport.

Scott.