Vertical Center Boxes

css

.block {
  text-align: center;
  background: #c0c0c0;
  border: #a0a0a0 solid 1px;
  margin: 20px;
}
 
.block:before {
  content: '';
  display: inline-block;
  height: 100%;
  vertical-align: middle;
  margin-right: -0.25em; /* Adjusts for spacing */
    
  /* For visualization
  background: #808080; width: 5px;
  */
 }
 
.centered {
  display: inline-block;
  vertical-align: middle;
  width: 300px;
  padding: 10px 15px;
  border: #a0a0a0 solid 1px;
  background: #f5f5f5;
 }

example

http://jsfiddle.net/chriscoyier/hJtpF/

html

<div class="block" style="height: 300px;">
    
    <div class="centered">
        <h1>Some text</h1>
        <p>But he stole up to us again, and suddenly clapping his hand on my shoulder, said&mdash;"Did ye see anything looking like men going towards that ship a while ago?"</p>
    </div>
    
</div>

<div class="block" style="height: 200px;">
    
    <div class="centered">
        <h1>Some text</h1>
        <p>But he stole up to us again, and suddenly clapping his hand on my shoulder, said&mdash;"Did ye see anything looking like men going towards that ship a while ago?"</p>
    </div>
    
</div>

<div class="block" style="height: 600px;">
    
    <div class="centered">
        <h1>Some text</h1>
        <p>But he stole up to us again, and suddenly clapping his hand on my shoulder, said&mdash;"Did ye see anything looking like men going towards that ship a while ago?"</p>
    </div>
    
</div>