I just open sourced my “send to calendar” chrome extension. I got tired of re-typing event info all the time, so the extension allows you to select text on any webpage, and send it to google calendar (with some smart parsing in between). The whole thing is super simple, and pull requests are welcome (particularly for additional parsing, support for international date formats, etc). You can find the whole thing on github, the guts are really just this background.js file:

//create the context menu 
var cmSendToCalendar = chrome.contextMenus.create({ "title": "Send To Calendar", "contexts": ["all"], "onclick": SendToCalendar });
//do all the things
function SendToCalendar(data, tab) {
	var location = "";
	var selection = "";
	if (data.selectionText) {
		//get the selected text and uri encode it
		selection = data.selectionText;
		//check if the selected text contains a US formatted address
		var address = data.selectionText.match(/(\d+\s+[':.,\s\w]*,\s*[A-Za-z]+\s*\d{5}(-\d{4})?)/m);
		if (address) 
			location = "&location=" + address[0];
	//build the url: selection goes to ctext (google calendar quick add), page title to event title, and include url in description
	var url = "http://www.google.com/calendar/event?action=TEMPLATE&text=" + tab.title + location +
	"&details=" + tab.url + "  " + selection + "&ctext=" + selection;
	//url encode (with special attention to spaces & paragraph breaks) 
	//and trim at 1,000 chars to account for 2,000 character limit with buffer for google login/redirect urls
	url = encodeURI(url.replaceAll("  ", "\n\n")).replaceAll("%20", "+").replaceAll("%2B", "+").substring(0,1000);
	//the substring might cut the url in the middle of a url encoded value, so we need to strip any trailing % or %X chars to avoid an error 400
	if (url.substr(url.length-1) === "%") {url = url.substring(0,url.length-1)}
	else if(url.substr(url.length-2,1) === "%" ) {url = url.substring(0,url.length-2)}
	//open the created url in a new tab
	chrome.tabs.create({ "url": url}, function (tab) {});
//helper replaceAll function
String.prototype.replaceAll = function(strTarget, strSubString){
	var strText = this;
	var intIndexOfMatch = strText.indexOf( strTarget );
	while (intIndexOfMatch != -1){
		strText = strText.replace( strTarget, strSubString )
		intIndexOfMatch = strText.indexOf( strTarget );
	return( strText );