Download an app called "where's my droid?"..when someone texts Where's my droid? to your phone, it will go full blast and ring until you find it, even if on silent
Yes its called Lookout Mobile Security.
Or, you can get to another phone and call yourself and follow the ringtone. But yes, Lookout does have the ability to track your phone.
Calling your phone won't work if you keep it on silent, like I have to at work. But no matter if its set to silent or vibrate, Lookout will make it produce a loud "scream"