One of the biggest problems with any user interface is ensuring the forms and controls are simple and straight forward to use. While Symfony comes with a great many of widgets that you can use in your forms, some of the most common ones are not as user friendly as one would hope.
Over the next week or two I will be releasing (and posting about) a number of symfony widgets that I've powered up with a little (or in some cases, a lot) of javascript. The first step, though, will be a plugin that adds jQuery and jQuery UI into your Symfony stack.