Apple Thoughts: PDF Expert From Readdle Updated to v1.5

"PDF Expert is the ultimate solution for all your PDF needs. It lets you read and annotate PDF documents, highlight text, make notes, draw with your finger and save these changes being compatible with Preview and Adobe Acrobat!"

The latest update to this program for the iPad adds the ability to put in your signature as well as fill in the fields of a scanned PDF. You can also modify documents from iDisk, Google Doc and Dropbox. You can find out more about it at the Readdle site, or go to iTunes [affiliate link]. There is also a similar app that works as a universal app for iPhone and iPad [affiliate link], however it doesn't have the ability to fill in the forms.