Video tours and photos.
[A little history, a rant or two and all credit to Alex.]

Not so many years ago, there was a single photo attached to a given listing.  Even after MLS listings could be loaded electronically, he photo had to be sent to TREB, who took a day or so to add it to the listing. So, the first day or so, the top left corner of the listing said "Photo Not Available".  One option to speed the process a touch was to use the TREB file photo of the property.  Unfortunately, sometimes the staff photo guy didn't seem to have stopped the car, let alone get out of it, to snap the shot. You may have guessed that the Google StreetView vehicles and their technology did not arrive for quite a while.

A technology that did arrive was digital video and the video tour.  Treating potential buyers to a movie of the whole home on their computer was pretty snazzy and useful.  But time consuming and expensive -- the first vid tour companies showed up at the house with a high tech van and a crew!

Next came "efficiency".  A fisheye lens, tripod and motor allowed a single tech to stick the tripod in the middle of each room, start the motor, try to stay out of the frame, and stitch all the room pans together the next day.

Unfortunately, this technology made all the rooms look like bowls with bowed walls and seconds-long pans of blank wall before you got to the good stuff.

About the same time TREB caught up a bit and started allowing 9 photos to be attached to a listing. By now, we could directly upload the photos at the same time as the listing itself.

So we stopped using video tours.  They not only distorted, but they disappointed buyers by making the places look bigger than reality. We prefer to under-promise by a hair, and over-deliver by a lot.

But then came Alex Morias of  www.videolistings.ca.  He was more advanced in the technology, but he regressed appropriately in technique. Armed with a video camera and a still camera, he took pans of the good stuff and key elements, put them together with stock footage, music and captions.  And it was beautiful.  An excellent representation of the property and a wonderful souvenir for buyers and sellers.  
Turned around the same day! 

So, with all that available, how is it possible that there are still listings that, for the first two days, still have "Photo Not Available" in the top left corner?!  It boggles the mind.  You can almost here the internet generation (of buyer and agent) clicking "next" and I think I can also here the memory of that listing clattering down a dusty corridor of the mind, to be never heard from again.