A post it note using CSS and HTML From http://hjerpbakk.com/blog/2012/7/30/how-to-move-from-blogger-to-squarespace.html

postIt.html

<!-- Dim the background, aka the blog -->
<div style='height:100%;    
width:100%;    
position:fixed;    
left:0;    
top:0;    
z-index:1 !important;    
background-color:black; 
filter: alpha(opacity=75); 
/* internet explorer */ -khtml-opacity: 0.75;      
/* khtml, old safari */ -moz-opacity: 0.75;       
/* mozilla, netscape */ opacity: 0.75;           
/* fx, safari, opera */ '/>

<!-- The style of the post it note -->
<div style="background: rgb(255,255,136); /* Old browsers */
background: -moz-linear-gradient(-45deg, rgba(255,255,136,1) 77%, rgba(255,255,214,1) 100%); /* FF3.6+ */
background: -webkit-gradient(linear, left top, right bottom, color-stop(77%,rgba(255,255,136,1)), color-stop(100%,rgba(255,255,214,1))); /*Chrome,Safari4+*/
background: -webkit-linear-gradient(-45deg, rgba(255,255,136,1) 77%,rgba(255,255,214,1) 100%); /* Chrome10+,Safari5.1+ */
background: -o-linear-gradient(-45deg, rgba(255,255,136,1) 77%,rgba(255,255,214,1) 100%); /* Opera 11.10+ */
background: -ms-linear-gradient(-45deg, rgba(255,255,136,1) 77%,rgba(255,255,214,1) 100%); /* IE10+ */
background: linear-gradient(-45deg, rgba(255,255,136,1) 77%,rgba(255,255,214,1) 100%); /* W3C */
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#ffff88', endColorstr='#ffff88',GradientType=1 ); /* IE6-9 fallback on horizontal gradient */
padding:15px;
font-family: 'Gloria Hallelujah', cursive;
font-size:15px;
color: #000;
width:300px;
height:200px;
position: fixed; top: 50%; left: 50%; margin-top: -100px; margin-left: -150px;
-moz-transform: rotate(7deg);
-webkit-transform: rotate(7deg);
-o-transform: rotate(7deg);
-ms-transform: rotate(7deg);
transform: rotate(7deg);
box-shadow: 0px 4px 6px #333;
-moz-box-shadow: 0px 4px 6px #333;
-webkit-box-shadow: 0px 4px 6px #333;
-webkit-border-bottom-right-radius: 60px 5px;
-moz-border-bottom-right-radius: 60px 5px;
-o-border-bottom-right-radius: 60px 5px;
z-index:2 !important; ">

<!-- The actual content of the post it note -->
<h3>My blog has moved</h3>
<p>You will be automatically redirected to the new address.</p>
<p>If that does not occur, please visit <a href='http://hjerpbakk.com/blog'><strong>http://hjerpbakk.com/blog'</strong></a>.</p>
</div>