Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
It's on either your iLife disc or the OS X disc that came with your computer (select "other software", don't reinstall the whole OS).
 
Make sure you actually deleted it. From Finder, click the Go menu, and select Applications. If it isn't in there, you deleted it.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.