We often get requests from people wanting to backup all the file attachments that are associated with their applications. A quick way to do that is to use QuickBase Desktop. QuickBase Desktop is a Microsoft Access database that synchronizes data between QuickBase and a local computer. When you do the synchronization, QuickBase desktop creates a folder in the same directory as the Access file for all the related documents and pulls all file attachments down to that folder. If you're interested in doing this, checkout the following Knowledgebase article. It has the Access file attached and it talks about how to automate the download.
I hope this helps!