How to transfer a file from iPhone to computer when there is no Internet?
Solution 1:
If you can transfer the document to a general-purpose app that "knows" about files (like GoodReader, Air Sharing, or iBooks), you should be able to access it from the file-handling dialog from within iTunes.
Most computers can create an ad-hoc WiFi network; using this, you'd use a network-sharing app (like Air Sharing) to mount a disk from your iPhone and transfer the files to your computer.
Solution 2:
The PhoneView program can read files from iOS devices through USB and get them to your mac in most cases.