How to add a “What is your question?” field at the top of all your pages so users can start asking a question from anywhere. I posted screenshots on the Meta Stack Exchange site, but wanted to post more detail here for others to get at.

Submitting the form takes you to the normal Ask Question page, pre-populates the form with your question, and displays any related questions above the form field.

Below is the code to implement a generic version of this form. I removed any style attributes that were specific to Petnibs.

CSS
Add to the theme custom CSS field

/* ========================= */
/* Ask Question				 */
/* ========================= */

#content { margin-top: 64px; }

#ask-question-form {
	padding: 0px;
	position: relative;
	top: 88px;
	width: 470px;
}

#ask-question-form form {
	margin: 0px;
	padding: 0px;
}

#ask-question-form input {
	font-size: 17px;
	float: left;
	width: 348px;
}

#ask-question-form button {
	cursor: pointer;
	float: left;
	font-size: 130%;
	font-weight: bold;
	height: 31px;
	line-height: 31px;
	margin: 5px;
	padding: 0px 8px;
}

/* ========================= */
/* Search results			 */
/* ========================= */

#search-title {
	margin-top: 18px;
}

#search-message {
	color: #F00;
	line-height: 18px;
	margin-top: 18px;
}

#search-results {
	max-height: 165px;
	overflow: auto;
	width: 665px;
}

#search-results .question-summary {
	padding-bottom: 2px;
	padding-top: 2px;
	width: 640px;
}

#search-results .summary {
	width: 450px;
}

#search-results h3 {
	font-size: 14px;
	margin-bottom: 2px;
	margin-top: 2px;
}

#search-results .search-text {
	font-size: 11px;
	line-height: 13px;
}

#search-suggest {
	color: #888;
	padding-left: 8px;
}

Ask Question Quick Form Code
Add to the end of the Linkbar content field

Ask

<div id="ask-question-form">

	<form action="/questions/ask" method="get">
		<input id="question" name="question" type="text" value="What is your question?" />
		<button>Ask</button>
	</form>
</div>

Ask Question Form Code
Add both sets of code to the end of the Question Help content field. For the second block, wrap it with <script type=”text/javascript>…</script>.

<style type="text/css">
#ask-question-form { display: none; }
#content { margin-top: 45px; }
#question-suggestions { display: none; }
</style>

Look for //modify and tweak those lines to your preference.

// Insert new elements
$("#post-form").before('<div id="search-message" style="display: none;"></div>');
$("#post-form").before('<h3 id="search-title" style="display: none;"></h3>');
$("#post-form").before('<div id="search-results" style="display: none;"></div>');
// Set question title field from url.question if blank
$().ready(function() {
	if ($("#ask-error-container").length == 0) {
		if ($("#title").val().length == 0) {
			if ($.getUrlVar('question').length > 2) {
				$("#title").val($.getUrlVar('question'));
				QuestionSuggestions();
			}
		}
	}
});
// Override QuestionSuggestions()
QuestionSuggestions = function() {
	var s = $("#title").val();            
	if (s.length > 2) {
		document.title = s + " - [site_name.com]"; // Modify
		$.ajax({
			url: "/search/titles?like=" + escape(s),
			cache: false,
			success: function(data){
			$("#question-suggestions").html(data);
				process_results();
			}
		});
	}
}
// Plugin to retrieve URL variables	
$.extend({
	getUrlVars: function(){
		var vars = [], hash;
		var hashes = window.location.href.slice(window.location.href.indexOf('?') + 1).split('&');
		for(var i = 0; i < hashes.length; i++)
		{
			hash = hashes[i].split('=');
			vars.push(hash[0]);
			vars[hash[0]] = hash[1];
		}
		return vars;
	},
	getUrlVar: function(name){
		var return_string = $.getUrlVars()[name];
		return_string = jQuery.trim(return_string).replace(/\+/g,' ');
		return unescape(return_string);
	}
});
// Display related results
function process_results() {
	var results = $("#question-suggestions").html();
	var htmlString = "";

	results = jQuery.trim(results);

	if (results != "That's not a very good title. Can you add some more unique words to it?") {

		// Change results to related questions list, clear out any previous results, show count
		results = $(".answer-summary");
		$('#search-results').html('');
		$('#search-title').html('Related Questions (' + results.length + ')');

		// Loop over related questions and create new HTML string to display results
		$.each(results, function(i, n) {

			var htmlString = "<div class='question-summary narrow id-"+i+"'>";
			var textString = "";

			// Add question votes
			htmlString += "<div class='search-link'>" + $(this).find(".answer-link").html() + "</div>";

			// Add answer votes
			votesCount = $(this).find(".answer-votes").text();
			if ( votesCount == 1) { votesString = "<div>vote</div>"; } else { votesString = "<div>votes</div>"; }
			htmlString += "<div class='votes'><div class='mini-counts'>" + $(this).find(".answer-votes").text() + "</div>" + votesString + "</div>";

			// Add title
			htmlString += "<div class='summary'><h3>";
			htmlString += "<a href=" + $(this).find("a.question-hyperlink").attr("href") + ">";
			htmlString += $(this).find(".question-hyperlink").text();
			htmlString += "</a></h3>";

			// Add summary
			htmlString += "<div class='search-text'>" + $(this).find("a.question-hyperlink").attr("title") + "</div>";
			htmlString += "</div></div>";

			// Insert into DOM
			$('#search-results').append(htmlString);

			// hacky : Remove href from answer-link, string spaces and parentheses, replace content
			$('#search-results .id-'+i+' a.question-hyperlink').remove();
			textString = $('#search-results .id-'+i+' .search-link').text();
			textString = textString.replace(/[\(\)\.\-\s,]/g,'');
			if (textString == '') { textString = "<div class='status'><div class='mini-counts'>0" } else { textString = "<div class='status answered'><div class='mini-counts'>" + textString };
			if ( textString == 1) { answersString = "<div>answer</div>"; } else { answersString = "<div>answers</div>"; }
			textString =  textString + "</div>" + answersString + "</div>";
			$('#search-results .id-'+i+' .search-link').replaceWith(textString);

		});

		$("#search-message").html("Your question may have already been asked.<br />Please review the following related questions before submitting a new one."); // Modify
		// Show related search results
		$("#search-message").show("fast");
		$("#search-title").show("fast");
		$('#search-results').show("slow");

	}
	else {

		$("#search-message").html("Your question seems too short. Are there additional unique words you can add to it?"); // Modify
		// Show results - message only
		$("#search-message").show("fast");
		$("#search-title").hide();
		$('#search-results').hide();
	}
}