[jhbarlow]"Will an apple computer run better if large files are stored on the hard drive rather than on the desktop?"
The "Desktop" is simply a directory (folder), in your home directory, on your system drive, that fills up your screen and provides a visual workspace. Its icons, as in any folder, represent files on your hard drive, that happen to be living in a "Desktop" folder. It's not some mysterious storage area hiding under a rock inside your computer. Under Mac OS 9, the desktop actually was not a good place for longterm, large file storage, for various reasons. Under OS X that's not an issue, except that organizationally, it's not good file management practice. As mentioned elsewhere, you should be saving captured media to a drive other than your system drive. Organize apps, documents, etc in appropriate folders. Use the Desktop for temporary stashing of zipped downloads, docs, etc, before moving them to more appropriate locations. You can create desktop aliases (shortcuts) to particular items, or learn how to use the Dock for similar purposes.