excerpt from http://github.com/gr2m/Mad-Lips-Forms

CSS for Mad Libs styie forms

.mad-lips label {
	white-space: nowrap;
	padding: 0 0 .5em;
	
    display: -moz-inline-stack;
    display: inline-block;
    vertical-align: top;
    zoom: 1;
    *display: inline;
}
.mad-lips input {
	font: inherit;
	background: transparent;
	border: none;
	border-bottom: 1px solid #111;
	outline: 0;
	display: block;
}
.mad-lips label span {
	font-size: .8em;
	line-height: 1em;
	opacity: .7;
	filter: alpha(opacity = 70);
}

example HTML for Mad Libs

<form action="" method="get" accept-charset="utf-8">
  <p class="mad-lips">
    Hello, my name is
    <label>
      <input type="text" name="firstname" value="" />
      <span>firstname</span>
    </label>
    <label>
      <input type="text" name="lastname" value="" />
      <span>lastname</span>
    </label>
    and I'm writing you today to learn more about the <strong>2003 HONDA ACCORD LX</strong> listed for <strong>$8,455</strong>. I live in the
    <label>
      <input type="text" name="zip" value="" />
      <span>ZIP</span>
    </label>
     area and I would like to hear back from you soon and learn more about this vehicle. Please call me at
    <label>
      <input type="text" name="zip" value="" />
      <span>my phone number</span>
    </label>
    at your earliest convenience.
  </p>
  <p><input type="submit" value="submit" /></p>
</form>