Yes, clipart is awesome, especially if you're in a hurry. But clipart is also generic and equally accessible to you and your competitors. In addition, the more specific your needs, the less likely it is you'll find what you need in any kind of clipart collection. Professional photography might provide a solution, but sometimes only an illustration will do, such as an image of something that doesn't exist (for example, the "exploded" battery among the images shown below).
Whether you're looking for illustrations that are cartoon-like or photo-realistic, The ArtD'partment can provide the custom — and professional — touch you want and need.