Creating nice dmg "installer" for Mac OS X

Bringing this question up to date by providing this answer.

appdmg is a simple, easy-to-use, open-source command line program that creates dmg-files from a simple json specification. Take a look at the readme at the official website:

https://github.com/LinusU/node-appdmg

Quick example:

1. Install appdmg

   npm install -g appdmg
   

2. Write a json file (spec.json)

   {
     "title": "Test Title",
     "background": "background.png",
     "icon-size": 80,
     "contents": [
       { "x": 192, "y": 344, "type": "file", "path": "TestApp.app" },
       { "x": 448, "y": 344, "type": "link", "path": "/Applications" }
     ]
   }
   

3. Run program

   appdmg spec.json test.dmg
   

(disclaimer. I'm the creator of appdmg)

It's fairly easy - the basic idea is that you create a blank image using Disk Utility (make it big enough to at least hold your stuff - exact size doesn't matter), open that image using Finder, put your stuff in and arrange it the way you want it (use right-click and Show View Options to set things like icon size or background image). That's almost it - all that remains is to convert that r/w image into a compressed image: eject it and use Convert in Disk Utility to convert it into a compressed image.