Question: How can I add an icon to my Rails application (to show in tabs when opened in a browser, etc.)?

Answer: 
Just so people know, the "document root" where you place your favicon.ico is the "public" folder. As a Rails newb I thought it would be in the root of the entire application. 

Also, you may have to clear your cache for it show up.
Put the `favicon.ico` under your `public/` folder and then add `<%= favicon_link_tag '/favicon.ico' %>` to your `<head></head>`

Then if you try it and doesn't work out, even after you cleaning browser's cache, you should try run the server at a different port. By default, rails runs the server at port 3000. 

Try changing the port to something you haven’t used before – run the app as:

RAILS 3: rails server -p 12345

RAILS 1/2: ruby script/server -p 12345