One of the advantages of having a camera on your iPhone and iPad is that you can you use it with great apps like Scanner Pro that let you take photos of documents to "scan" them and store as PDFs. The result looks just as if you used a physical scanner to do the job.
Brookstone is set to launch an iPad specific hardware scanner in February. The scanner has been designed for the road warrior that no longer wants or needs to carry around a laptop, but needs to regularly scan documents on the go .