Letter size

<script language="JavaScript" src="http://bloghacktips.googlepages.com/font.js"></script><div class="central" style="width: 80; height: 19"><span style="font-family:Arial;"><b><br /><br /><a href="javascript:decreaseFontSize();">A-</a><span style="font-size: 200%"> <a href="javascript:increaseFontSize();">A+</a></span></b></span></div><a href="http://bloghacktips.blogspot.com/2009/04/font-size-is-always-problem-for-blogger.html"><span style="font-size: 70%"></span></a>

Το βρήκα εδώ