тогда уж вот современное:
<!DOCTYPE HTML>
<html>
<head>
<style type="text/css">
div {
display: table-row;
}
div.table {
display: table;
width: 100%;
}
div p {
height: 40px;
display: table-cell;
vertical-align: middle;
background: #eee;
}
div:nth-child(2n) p
{
background: #ddd;
}
</style>
</head>
<body>
<div class="table">
<div><p>this is div number 1</p></div>
<div><p>this is div number 2</p></div>
<div><p>this is div number 3<br />ОПА!!!!</p></div>
<div><p>this is div number 4</p></div>
<div><p>this is div number 5</p></div>
</div>
</body></html>