diff --git a/resources/pinout.css b/resources/pinout.css
index ede310a..19ef3bb 100644
--- a/resources/pinout.css
+++ b/resources/pinout.css
@@ -80,6 +80,7 @@ nav#gpio ul.bottom {
 	top:17px;
 	list-style:none;
 }
+
 nav#gpio ul.top li {text-indent:52px;}
 nav#gpio li a {
 	display:block;
@@ -89,41 +90,53 @@ nav#gpio li a {
 	line-height:29px;
 	height:27px;
 	margin-bottom:2px;
-}
-nav#gpio li a small {font-size:11px;}
-
-nav#gpio li.overlay-pin a {
-	background:rgba(235, 230, 211, 0.50);
 	border-top-left-radius:13px;
 	border-bottom-left-radius:13px;
 }
-nav#gpio ul.bottom li.overlay-pin a {
-	background:rgba(235, 230, 211, 0.50); /*rgba(6, 53, 65, 0.50);*/
-	color:#063541;
+nav#gpio ul.bottom li a {
 	border-top-right-radius:13px;
 	border-bottom-right-radius:13px;
 	border-top-left-radius:0px;
 	border-bottom-left-radius:0px;
 }
 
+nav#gpio li a small {font-size:11px;}
+
+
+
 nav#gpio li a:hover,
 nav#gpio li.active a {
 	background:#063541;
 	/*background:#EBE6D3;*/
 	color:#FFF;
-	border-top-left-radius:13px;
-	border-bottom-left-radius:13px;
 }
 
 nav#gpio ul.bottom li a:hover,
 nav#gpio ul.bottom li.active a {
 	background:#063541;
 	color:#FFF;
-	border-top-right-radius:13px;
-	border-bottom-right-radius:13px;
-	border-top-left-radius:0px;
-	border-bottom-left-radius:0px;
 }
+
+
+nav#gpio li.overlay-pin a {
+	background:rgba(235, 230, 211, 0.50);
+	color:#063541;
+}
+nav#gpio ul.bottom li.overlay-pin a {
+	background:rgba(235, 230, 211, 0.50); /*rgba(6, 53, 65, 0.50);*/
+	color:#063541;
+}
+
+article .pin-hover {cursor:help;}
+article .pin-hover:hover {color:#880000;}
+
+
+nav#gpio ul li.hover-pin a,
+nav#gpio ul.bottom li.hover-pin a {
+	color:#FFF;
+	background:rgba(200,0,0,0.6);
+}
+
 nav#gpio ul.bottom a {
 	text-indent:10px;
 }
diff --git a/resources/pinout.js b/resources/pinout.js
index fb02a19..22ac56d 100644
--- a/resources/pinout.js
+++ b/resources/pinout.js
@@ -17,4 +17,30 @@ jQuery(document).ready(function(){
 		trackFTP: false
 	})
 
+	$('article p').each(function(){
+		html = $(this).html();
+
+		html = html.replace(
+			/Physical\ Pin\ ([0-9]{1,2})/gi,
+			function(str, c1){
+				return '<span class="pin-hover" data-pin="' + c1 + '">' + str + '</span>';
+			}
+		)
+
+		$(this).html(html);
+	});
+
+	$('article p .pin-hover').hover(function(){
+		var pin = $(this).data('pin');
+		$('li.pin' + pin).addClass('hover-pin');
+	},function(){
+		var pin = $(this).data('pin');
+		$('li.pin' + pin).removeClass('hover-pin');
+	});
+
+	$('article p').on('click','.pin-hover',function(){
+		var pin = $(this).data('pin');
+		$('li.pin' + pin + ' a').trigger('click');
+	})
+
 });
diff --git a/src/en-GB/description/overlay/ground.md b/src/en-GB/description/overlay/ground.md
new file mode 100644
index 0000000..7a5d1d2
--- /dev/null
+++ b/src/en-GB/description/overlay/ground.md
@@ -0,0 +1,10 @@
+#Ground
+
+The Ground pins on the Raspberry Pi are all electrically connected, so it doesn't matter
+which one you use if you're wiring up a voltage supply.
+
+Generally the one that's most convinient or closest to the rest of your connections is tidier
+and easier, or alternatively the one closes to the supply pin that you use.
+
+It's a good idea to use Physical Pin 17 for 3v3 and Physical Pin 25 for ground when using
+the [SPI](/pinout/spi) connections, for example, as these are right next to the important pins for SPI0.
\ No newline at end of file