Through March 15, 2012, Singapore Airlines (and SilkAir) passengers arriving in Singapore from China, Egypt, India, Japan, Korea, Saudi Arabia, South Africa, Taiwan, Turkey and the US, and connecting to another Singapore or SIlkAir flight, are eligible for a SGD$20 voucher.
Information counters in terminals 2 and 3 have the vouchers, and require you to show a printout of your e-ticket receipt and the boarding pass from your arriving flight.
The vouchers don’t have to be used on the same trip, they expire on March 15.
Each is valid for one-time use at all retail, food and service outlets located at the transit and public areas of Terminals 1, 2 and 3 (but are not valid in the arrival baggage claim halls).
Interestingly, that means they’re valid for access to the paid Ambassador Transit Lounge for up to three hours. So anyone arriving from an eligible destination on Singapore and connecting to another Singapore flight has lounge access with showers, drinks, wireless internet, etc. in the lounge. Singapore coach connecting passengers get some basic lounge access through mid-March.