When you download apps from the Android Market, they are stored onto the internal memory.
The thing about Android devices is there is no /usr/local/bin/ directory like on Linux where the apps could be stored. They are stored somewhere else. (I'm not very familar where Java applications are stored on my computer.)
On Android devices, the SD card is mounted to the path /sdcard/
This path become unavailable on the Android device because it is busy being the SD card on the computer.
Because one of the software publishers, Robot Comics, suggest moving any of their e-ComicBooks from the internal memory to the SD card then using the Android Comic Reader to read the files from the SD card, how do I movie these documents to the SD card and where are they to begin with?
(Tip: Create a directory on you SD card called "Books" for storing e-Books, "Music" for storing music, and "Documents" for other stuff. Your photos directory is actually in the directory /sdcard/dcim/Camera.)