grunt.js

config.init({
	meta: {
		title: 'Premier Dental Implant Practices',
		name: "Christopher Webb",
		homepage: 'http://conspirator.co',
		twitter: 'conspirator',
		banner: '/* \n' +
				' * \tAuthor:\t\t{{meta.name}}\n' +
				' * \tWebsite:\t{{meta.homepage}}\n' +
				' * \tTwitter:\thttp://twitter.com/{{meta.twitter}}\n' +
				' * \n' +
				' * \tTitle:\t\t{{meta.title}}\n' +
				' * \tBuild:\t\t{{today "yyyyddmm"}}\n' +
				' * \n' +
				' */'
	},
	watch: {
		files: ["assets/js/*.js"],
		tasks: 'default'
	},
	concat: {
		'assets/js/min/main.js': ["assets/js/jquery-1.7.1.min.js", "assets/js/underscore.min.js", "assets/js/jquery.cycle.all.js", "assets/js/jquery.validate.js", "assets/js/jquery.lightbox_me.js", "assets/js/main.js"],
	},
	min: {
		'assets/js/min/main.min.js': ['<banner>', 'assets/js/min/main.js']
	}
});

// Default task.
task.registerTask('default', 'concat min watch');

FWIW, you can use wildcards in your watch files list to simplify things, like:

config.init({
  watch: {
    files: ["assets/js/*.js"],
    tasks: "default"
  }
});

Thanks, this provides a useful example as all I wanted was to use it for JS minification too. How do you get the meta banner outputting though? For me it outputs literally like this:

/* 
 *  Author:     {{meta.name}}
 *  Website:    {{meta.homepage}}
 * 
 *  Title:      {{meta.title}}
 *  Build:      {{today "yyyyddmm"}}
 * 
 */