I was a bit of a late-comer to the JQuery party, but now I've been using it for a while it's given me a host of options for adding extra flair to the client side of my applications. Here's a few generic JQuery functions I've written which can be used to add some neat little features to a page. Just call any of them from a document ready function.

Apply JQuery Themeroller Styles to all Page Buttons

  The JQuery Themeroller is a great tool for creating a theme for a site based on colours and styles for particular page elements. The JQuery.UI library then provides a set of functions which allow you to apply styles to page elements. This function applies a JQuery Themeroller style to all the buttons on a page - as well as any elements which have a button class applied to them - and then makes the mouse pointer turn into a cursor when you mouse over them:

function addCursorPointerToButtons() {
    $("button, input[type='submit'], input[type='button'], .button")
        .button().css("cursor", "pointer");
}

Automatically Remove the Default Value from a Select Box

  Required drop-down select boxes often have a default option which reads 'Please select...' (or something like that), but once someone has selected a value, there's no need to retain that. This function removes the default option from any select boxes on the page which have a data-val-remove-default attribute once one of the non-default options has been chosen:

function removeDefaultSelectOptionOnSelect() {
    $("select[data-val-remove-default='']").change(function () {
        var sel = $(this);
        if (sel.val() != "") { 
            sel.children("option[value='']:first").remove();
        }
    });
}

Automatically add a Required Label and Stars to a Form

  It's pretty standard to have a little * next to required form field elements. This function adds the text * Required to the top of the first form on the page, and adds *s to any element within the form with the class editor-label and a data-val-required attribute:

function addRequiredFieldLabels() {
    var elements = $(".editor-label[data-val-required='']");
    if (!elements.length) { return; }
    var requiredString = "<div class='editor-required-key'>* Required</div>";
    var prependString = "<span class='editor-required-label'> * </span>";
    var firstFormOnThePage = $("form:first");
 
    if (!firstFormOnThePage.children('div.editor-required-key').length) {
        firstFormOnThePage.prepend(requiredString);
    }
 
    elements.each(function (index, value) {
        var formElement = $(this);
        if (!formElement.children('span.editor-required-label').length) {
            formElement.prepend(prependString);
        }
    });
}

I hope those come in handy :)