Check in to Facebook Fan Page for your restaurant. 
1.  Try and setup a Fan Page.
2.  Create a nice image for your fan page.
3. Market your fan page in your restaurant.  Maybe at the front desk can say join us at facebook ************
4. Create coupons on your fan page to keep people going back to it.
5. Use Facebook adwords to market to people in your town.  Number 5 is very powerful if don right.
6.  Create a feed back page on you Fan Page
7.  Last update it every day with soup of the day happy hour and events that are going on. 
When facebook users start using your Fan Page it will share it with their friends.  Soon you will get more likes on your fan page and then they will start showing up at your restaurant.
Have fun with it…
If you need help or want more info contact me at [email protected]