Smart Quotes – changes straight double and single quotes to curly, double dashes to em-dashes, and triple periods to ellipsis.

smartquotes.js

// http://stackoverflow.com/a/14890774/484780
smartQuotes = function(str){
	return str = (str||'').replace(/\b'\b/g, "\u2019")			// apostrophes
			.replace(/'(?=[^>]*<)\b/g, "\u2018")     			// Opening singles
			.replace(/\b([\.\?\!,]*)(?=[^>]*<)'/g, "$1\u2019")	// Closing singles
			.replace(/"(?=[^>]*<)\b/g, "\u201c")     			// Opening doubles
			.replace(/\b([\.\?\!,]*)(?=[^>]*<)"/g, "$1\u201d")  // Closing doubles
			.replace(/\.\.\./g,  "\u2026")     					// ellipsis
			.replace(/--/g,  "\u2014")     						// em-dashes
}