When you have limited space on your home page or any other page for that matter, it is nice to provide a little more helpful information for the use where form space is limited. Now, by just adding a single attribute to your input text, your will get the gray help text in your input box.

<input hintvalue="Search ..." class="smallbox" name="s" type="text" autocomplete="off" />

Just add the javascript from this article and any styles that you want and you are done. Here is a working example. Click in the boxes and watch it work.