Chrome extension to list all tab locations and copy them to the clipboard

manifest.json

{
  "name": "Open URL Collector",
  "version": "1.0",
  "description": "Creates a list of the URLs of open tabs.",
  "browser_action": {
    "default_icon": "famfamfam_silk_cut_tab.png",
	"popup": "popup.html"
  },
  "permissions": ["tabs"]
}

popup.html

<!--
	===============================
	SCRIPT
	===============================
-->
<script type="text/javascript">
	/**
	 * The URLs
	 */
	var urls = [];
	
	/**
	 * Gather the information from the open tabs and construct the popup.
	 */
	function generate(tabs)
	{
		/*
		 * The function has been called without an array of tabs, so we much
		 * request them from Chrome, which will call the function again
		 * correctly with an array of the tabs open.
		 */
		if (!(tabs instanceof Array))
		{
			chrome.tabs.getAllInWindow(null, generate);
		}
		/*
		 * The function has been called with an array of tabs.
		 */
		else
		{
			var output = document.getElementById('output');
			var counter = document.getElementById('counter');
			
			// Reset the URLs
			urls = [];
			
			for (var i = 0; i < tabs.length; i++)
			{
				// Add the URL to the list
				urls.push(tabs[i].url);
				var url = urls[i];
				
				// Add the URL to the output
				output.appendChild(document.createElement("li")).innerHTML = url;
			}
			
			// Update the counter
			counter.innerHTML = urls.length;
		}
	}
	
	/**
	 * Copy the generated content to the clipboard.
	 */
	function copy(text)
	{
		var clip = document.getElementById('clip');
		
		// Default the clipboard text to that of the URLs separated by a \n
		if (text === undefined)
			text = urls.join("\n");
		
		// Set the clipboard text
		clip.value = text;
		clip.select();
		document.execCommand('Copy');
	}
	
	/**
	 * Entry point
	 */
	window.onload = function() {
		generate();
	};
</script>
<!--
	===============================
	STYLE
	===============================
-->
<style type="text/css">
	#clip {
		position: absolute;
		width: 10px;
		left: -20px;
	}
	body {
		font-family: sans-serif;
		font-size: 0.8em;
	}
	h1 {
		margin: 0;
		padding: 5px 0 0 0;
		font-size: 12px;
		float: left;
	}
	button {
		margin: 0 0 5px 0;
		float: right;
		padding: 3px 5px;
		font-size: 0.8em;
	}
	#output {
		width: 200px;
		overflow-x: scroll;
		
		margin: 0;
		padding: 5px;
		list-style-type: none;
		
		background-color: #EEE;
		border: 1px solid #CCC;
		
		font-family: sans-serif;
		font-size: 0.8em;
	}
	#output li {
		margin: 0;
		padding: 0;
		
		overflow-x: visible;
		white-space: pre;
	}
</style>
<!--
	===============================
	DOCUMENT
	===============================
-->
<textarea id="clip"></textarea>
<button onclick="copy();" title="Copy the open tabs' URLs to the clipboard.">Copy</button>
<h1><span id="counter">#</span> tabs open</h1>
<ul id="output"></ul>

famfamfam_silk_cut_tab.png: