Is there a way to store documents locally, on the iPad device itself. I have several documents (pdf, spreadsheets, etc) that I open up and refer to multiple times a day. I am not always in range of a wi-fi connection. I know I can store them in dropbox, but if I click on the document without being connected to the net it can’t download them to display.
No, you’re not missing anything. Storage is app specific. Some apps provide the ability to store documents locally, and some don’t. This is a design decision by Apple.
In the case of ebooks, Stanza stores both epub and PDFs on the device. I don’t know if Stanza’s around anymore though.
I wish I knew the name of an app that lets you save and display files, but I don’t, sorry.