neilgee

This plugin adds support for placeholder text in browsers that don’t support this HTML5 feature including Internet Explorer 6.
The plugin just activates the placeholders.js script by James Allardice http://jamesallardice.github.io/Placeholders.js/
There is no further configuration required.
For HTML input elements use the placeholder attribute and add a value, this value is removed when a user inputs the field. http://coolestguidesontheplanet.com/add-a-label-into-a-text-input-field-in-a-html-form/#html5
The script is 4KB and is set to load in the footer and has no library dependencies.
<h3>Usage</h3>
Just activate the plugin which loads the script, their is no further configuration.

Placeholder Text

This plugin adds support for placeholder text in browsers that don't support this HTML5 feature.

tmertz

Designed to make it easier to serve signup form on sites for LARP activities, this plugin aims to be very flexible in the way it handles input form fields.
What makes this plugin awesome is:
<ul>
<li>the ability for you to define the form you need to get the data you want.</li>
<li>the fact that it has been designed with the less is more paradigm in mind.</li>
</ul>
Thank you goes out to nkuttler of the IRC channel for his help sorting out my problems with $_POST.

Osmig Signup Plugin

This is a simple and flexible plugin to handle signups with the form fields you define.

Placeholder Text vs Osmig Signup Plugin