You wont be able to do that only with html, you need add some JS and for that there is many good plugins (one example: http://www.akshitsethi.me/pinterest-like-grid-layout-using-jquery/)
Another option (if you don`t need IE support - 10% of the users):
CSS3 Collumn. Easy and clean:
Check out this fiddle > http://jsfiddle.net/luckmattos/aExxp/1/ or www.w3schools.com "css3_multiple_columns" or...
HTML
<div>
<div class="item1">Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt ut laoreet dolore magna aliquam erat volutpat.</div>
<div class="item2">Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt ut laoreet dolore magna aliquam erat volutpat.</div>
<div class="item3">Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt ut laoreet dolore magna aliquam erat volutpat.</div>
<div class="item1">Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt ut laoreet dolore magna aliquam erat volutpat.</div>
<div class="item3">Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt ut laoreet dolore magna aliquam erat volutpat.</div>
<div class="item2">Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt ut laoreet dolore magna aliquam erat volutpat.</div>
<div class="item1">Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt ut laoreet dolore magna aliquam erat volutpat.</div>
<div class="item3">Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt ut laoreet dolore magna aliquam erat volutpat.</div>
<div class="item2">Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt ut laoreet dolore magna aliquam erat volutpat.</div>
</div>
CSS
div {
width:500px;
padding:10px;
background:#ccc;
/* Number of COLS */
-moz-column-count:2; /* Firefox */
-webkit-column-count:2; /* Safari and Chrome */
column-count:2;
/* Distance between COLS */
-moz-column-gap:10px; /* Firefox */
-webkit-column-gap:10px; /* Safari and Chrome */
column-gap:10px;
}
.item1 {
background:#f00;
height:100px;
padding: 3px;
margin:10px;
display:inline-block;
}
.item2 {
background:#0f0;
height:150px;
padding: 3px;
margin:10px;
display:inline-block;
}
.item3 {
background:#00f;
height:100px;
padding: 3px;
margin:10px;
display:inline-block;
}