Alas, you're out of luck if you didn't activate the Find my Phone app.
But all may not be lost. Keep looking. My daughter lost her iPod Touch about a year ago. Searched everywhere, then forgot about it. While looking for something else a few weeks ago, it was found in the side pocket of one of the family cars. She charged the battery overnight and it was as good as new.
Sometimes things will pop up where we least expect them.