Best of luck with this. In addition to what has been suggested:
- Go to Petfinder.com and register your lost pet
- If there is local Craig's List post there
- Let all vet offices know that your dog is missing
- Call the local authorities - there is usually someone who is in charge of this and they generally keep fairly good records about what they have found
- Don't just put up flyers - make thousands of them and put them on/in every door way, slip one under car's wind shield wipers. Talk to the person who delivers the mail - give him/her a flyer.
Don't lose hope - I lost one of my cats for 3 weeks in a very busy neighborhood (a friend was watching him and he got out). It was awful for 3 solid weeks but in the end, I found him. While I was looking for him everyone in the neighborhood got to know me. I would drive to my friend's neighborhood every night after work to look for him. I heard kids walking around calling my cat's name (they were looking for the cat but wanted the reward).
Please keep us posted, my thoughts and prayers are with you