In this new article from Noupe.com they link to several resources that can help you make your site's forms a bit "more beautiful" by combining PHP and Ajax (and Javascript).

Forms needs a solid visual structure, a profound hierarchy of form elements (Fields and Labels), powerful techniques and Functionality (AJAX) to make the form look and work creatively. [...] Today we wanted to share with you some great steps to get the perfect form: we will go through designing and usability you need to keep in mind, styling your form, spicing it up with some nice javascript effects, validating user’s input and finally getting it to work using PHP and Ajax.

Some of the links include:

• Web Form Design Patterns: Sign-Up Forms
• Justify elements using jQuery and CSS
• XHTML/CSS web forms: 5 simple techniques
• Using ProtoForm
• Autosuggest / Autocomplete with Ajax

Most of the article links also include links to demos of the tutorial/application in action.