From the above we may conclude devices which are good to run off USB bus power. USB gadgets such as digital cameras, reading small files off flash memory via a card reader, keyboards and any other low data transfer USB device.
Items which need an external power adapter would include, USB hard drives, external CD or DVD burners, video cameras, USB hubs [if using with any of the previous] and any other device with high data transfer rates. *Note: If you have large files on flash memory - use a card reader or USB hub with power adapter.
