Three cheers to ProgrammableWeb.com for pointing me toward Special Gourmets at http://www.specialgourmets.com/. This site lets you map hotels, restaurants and other destinations that accomodate several different diets: gluten-free, dairy-free, nut/peanut-free, shellfish-free, egg-free, and soy-free.
Just use the checkboxes to indicate what dietary needs you’re looking for. There’s another set of checkboxes that allows you to specify by service: whether you’re looking for places to eat or stay or buy food, and whether you want to include large chains. Special Gourmets will give you a map of the area you’re searching as well as a list of the restaurants if you like.
I did a search for all special diets in Denver, Colorado. Special Gourmets gave me 36 results. I took a look at the list and found several chains, including Chilis, Chipotle, and PF Changs. But there were also listings that looked like local restaurants, including Blue Bonnet Restaurant and a place called The 9th Door.
The restaurant listings show contact information and sometimes a picture, with icons that signify what dietary needs are accommodated and sometimes brief snippets of information. You can click on the restaurant name for additional information and sometimes more details like where you can get special diet information at the restaurant and the kinds of requests you can make.
Useful, and the icons make the maps very easy to browse.