What is virtual tour ?
You probably know what is 3D Panoramic photo. Now imagine that you have several panos from one area (for example restaurant or hotel). And if you connect these 3D panos with each other, you will get virtual tour.
You don't need any special equipment to create virtual tour. Just shoot panoramic images on locations you want to have in your tour. All you need is some special software to create this tour (to connect several 3D panos). I am using krpano for this. It's not the simpliest software to do this, but give a lot of freedom with possibilities. Some basic programming knowledge is needed.
If you want to see examples, please visit virtual tour website.