I can't tell from your ad if your cat is an indoor-only cat, but assuming that he is, I can tell you that indoor-only cats generally go into what's known as combat mode when they get out. They will hide nearby say within a block or two.(Maybe they'll find a place that doesn't have human or animal smells such as inside, near, or under empty houses.) They probably won't respond even if they hear their owner's voices. So, your cat is hunkered down, nearby.
If you don't find your cat in the mean time, after about eight days hunger will force your cat to come out and that's when you'll have a great chance of finding your cat. So, put up signs, again, at that time and be looking really late at night for your cat. After the eight days, your best time to find him is in the wee hours such as around 3am. Your cat will either be moving or your cat will sit somewhere where your cat has a good view such as under a car or at the foot of a driveway.
One other thing that you can do right away would be to hire tracker dogs. You can go to lostapet.org to see who does that in your area, if you'd like. It could cost you something like $900, though. But, maybe there will be someone close to you who does that for less. Might be worth checking. If you happen to live in an area with a whole lot of wild rabbits and therefore a lot of coyotes, then I recommend getting tracker dogs right away.
Good luck,
See other cat-finding tips at http://catflasher.com