On a Youth Olympic Games 2010 Brochure :
"To encourage the usage of public transport, every valid ticket
comes with the Singapore 2010 DBS Visa Prepaid Companion
Card that gives you unlimited free bus
rides and up to 4 free train rides for
that particular event day you are attending."
Considering that tickets start from $10... 
Actually if u are not really interested in attending the event,
could just get the singapore tourist pass... unlimited mrt and bus
rides for 1 day at $8