I'm very sorry about your kitty. Everyone here understands your heartbreak and terror that he won't come back.

There's only two things I could possible add to what you've done already. Where we live, the suburban newspapers let you place lost pet ads for free and they're carried in a network of suburbs.

The other thought is that you need to call to him. Meow to him. Read the story of lost Pete...turned out he wasn't far away and responded to her calls..

http://petoftheday.com/talk/showthread.php?t=84457

Good luck to you and your kitty. You have our prayers.

Oh, forgot to add that a co-volunteer put a flyer in a local convenience story and the people who found her cat called her within half an hour!