Since they seem to have risen to popularity in the format of a panoramic view of rooms in a home, with sweeping movement, sometimes in 360 degree panoramas, let's start with this definition. If this is the definition we're using, I agree, they're of little use. They frequently distort the rooms, make the visitor sit through a slow sweep, and many times actually make it more difficult to visualize the space.
But, some real estate professionals make a slide show of multiple photos, even breaking them into room-by-room shows. These can also be called virtual tours. Others take this approach one step farther and make these slide shows into videos that can play on YouTube and mobile platforms. If this is the approach, I think they're really quite effective. The trick is to make the transition speed such that the viewer isn't rushed, but they don't get bored either. Rather than making the visitor click for a new photo, they can just sit back and watch as they're taken through the home. This method allows for the highest quality depiction of the home, as the photos can be edited for brightness, contrast and other characteristics.
With the entrance of easy to use full motion camcorders, like The Flip, one type of virtual tour is a true video of the home. Viewers are escorted through the home by the listing broker, with audio in many cases to describe the rooms as they're recorded. While some carry the camera, others place it on a tripod for a less impromptu approach. While some of the worst real estate virtual tours I've seen were done with a handheld camcorder and voice-over, some of the best fall into this category as well.
While there definitely are real estate virtual tour methods that are no longer effective, using the right equipment, good taste, and doing quality editing can make a real estate virtual tour second only to an actual showing of the home.
