For a small application, you might have to do all of the work yourself. If you have ever built a whole application, you might remember that some parts were fun and others were less fun. And, while being functional, your application probably did not win any prizes for design or usability.

If your enterprise application is going to be a success, people should want to use it. That means it has to be visually attractive and user friendly—public sites such as Facebook, Flickr, and the various Google applications have set the bar fairly high. Your users expect the enterprise application that you are building to live up to the sites they see and use regularly.

These applications are not built by one person. They are large (like your application), so they need a sizable team of programmers. But, they are also complete—the visual identity and usability is as much a part of the overall experience as the code. If you are to live up to these high demands, you need a...