Wego (http://www.wego.com) was shared by my colleague when my another colleague ask for flight to Thailand.
Yeah, I find it useful.
Check this flight, Singapore To Manila, 25 Dec 2010 - 31 Dec 2010 , 1 Adult 
Wego doesn't sell travel. Wego helps YOU shop for travel. Wego allows you to browse hot deals, see a quick snapshot of prices or run a full real-time search.
-Wego