diff -ur smartypants.orig/smartypants.php smartypants.new/smartypants.php
--- smartypants.orig/smartypants.php	2007-10-18 21:53:40.000000000 -0400
+++ smartypants.new/smartypants.php	2007-12-04 22:44:08.000000000 -0500
@@ -159,6 +158,7 @@
 	var $do_backticks = 0;
 	var $do_dashes    = 0;
 	var $do_ellipses  = 0;
+	var $do_fractions = 0;
 	var $do_stupefy   = 0;
 	var $convert_quot = 0; # should we translate " entities into normal quotes?
 
@@ -179,6 +179,7 @@
 	# D : old school dashes
 	# i : inverted old school dashes
 	# e : ellipses
+	# f : fractions
 	# w : convert " entities to " for Dreamweaver users
 	#
 		if ($attr == "0") {
@@ -190,6 +191,7 @@
 			$this->do_backticks = 1;
 			$this->do_dashes    = 1;
 			$this->do_ellipses  = 1;
+			$this->do_fractions = 1;
 		}
 		else if ($attr == "2") {
 			# Do everything, turn all options on, use old school dash shorthand.
@@ -197,6 +199,7 @@
 			$this->do_backticks = 1;
 			$this->do_dashes    = 2;
 			$this->do_ellipses  = 1;
+			$this->do_fractions = 1;
 		}
 		else if ($attr == "3") {
 			# Do everything, turn all options on, use inverted old school dash shorthand.
@@ -204,6 +207,7 @@
 			$this->do_backticks = 1;
 			$this->do_dashes    = 3;
 			$this->do_ellipses  = 1;
+			$this->do_fractions = 1;
 		}
 		else if ($attr == "-1") {
 			# Special "stupefy" mode.
@@ -219,6 +223,7 @@
 				else if ($c == "D") { $this->do_dashes    = 2; }
 				else if ($c == "i") { $this->do_dashes    = 3; }
 				else if ($c == "e") { $this->do_ellipses  = 1; }
+				else if ($c == "f") { $this->do_fractions = 1; }
 				else if ($c == "w") { $this->convert_quot = 1; }
 				else {
 					# Unknown attribute option, ignore.
@@ -312,6 +317,8 @@
 			}
 		}
 
+		if ($this->do_fractions) $t = $this->educateFractions($t);
+
 		if ($this->do_stupefy) $t = $this->stupefyEntities($t);
 		
 		return $t;
@@ -507,6 +514,26 @@
 	}
 
 
+	function educateFractions($_) {
+	#
+	#	Parameter:	String.
+	#	Returns:	The string, with each instance of "i/j" translated to
+	#				a fraction HTML entity (for values of i,j for which an)
+	#				entity exists.)
+	#
+	#	Example input:	1/2 cup extra-virgin olive oil
+	#	Example output:	½ cup extra-virgin olive oil
+	
+		$fraction_entities = array('1/4' => '¼', '1/2' => '½', '3/4' => '¾');
+		$_ = preg_replace("{
+			\\b	# a word boundary
+			(1/4|1/2|3/4) # a fraction that'll be receptive to some book learnin'
+			\\b
+		}xe", '$fraction_entities["\\1"]', $_);
+		return $_;
+	}
+	
+
 	function stupefyEntities($_) {
 	#
 	#   Parameter:  String.
@@ -529,6 +556,9 @@
 
 		$_ = str_replace('…', '...', $_); # ellipsis
 
+		# fractions
+		$_ = str_replace(array('¼', '½', '&#190'), array('1/4', '1/2', '3/4'));
+
 		return $_;
 	}