Yes, PLEASE!
I'm not hip yet to all the exact terminology yet so I don't exactly know what off camera flash means. Are you referring to big umbrellas and soft boxes and the like? Or do you mean holding the flash in your hand, or an arm's length away from the camera via some kind of cord?
As requested:
Model is my 8 year old daughter. Camera was in P mode, ISO 400, flash in full automatic. I deliberately shot with her in front of a wall to give kind of a worst-case scenario for shadows, etc. No changes were made to any camera settings for the whole series.
Built-in flash:
Built-in flash, camera in portrait orientation:
SB-800, straight on:
SB-800, straight on with camera held vertically. Notice how much more offset her shadow is, we're starting to get away from the point and shoot shadow look.
SB-800, bounced straight up. In this one you will notice the dark eye sockets, caused by the fact that all the light is basically coming from above. This is an instant telltale of a bounce flash picture.
SB-800, bounced off the wall to the right. The SB-400 will operate this way if you have a nearby, white colored wall handy. This light is far better than straight on (nevermind the duh expression) but it's still a bit harsh and shadowy.
Camera held vertically, SB-800 flash bounced up to ceiling. Dark eyes again.
SB-800 bounced off side wall with a small fill card (white reflector to throw some light straight forward) This is probably the best light of the bunch. The side wall acts as a giant light source to evenly illuminate her left side, and the bounce card (literally, an index card taped onto the flash) throws enough light forward to fill in the shadows and smooth things out on her right (camera left). You can also see a reflection of the light in her eyes. This little sparkle adds an amazing amount of life to a portrait.
Off camera flash means anything not on the camera. I've shot with remote strobes mounted in the ceiling of a reception hall, softboxes, umbrellas, holding the flash above my head with my left hand and looking like a chimpanzee, and many other combinations as well. You can buy a TTL Flash cord for about $60-$70 that will allow you to get the flash about three or four feet away, which can do wonderful things for your light.
The flash in left hand thing works well for adults, but kids always end up looking at the flash instead of the camera

Still better than nothing, without the flash here the two kids would be as dark as the adults in the background.