Here’s a useful and free tool for seeing the filesystem of your iPhone and iPod Touch once it’s connected to your PC or Mac via USB cable and transferring files: DiskAid
Before this will work, you may have to ensure the following:
In Windows, the “Apple Mobile Device” service must be running
You should enter the Passcode on your iPhone or iPod Touch
The device must be jailbroken if you want to see anything outside the Media folder, e.g. if you want to see the root folder.