Hi /gd/.
These kinds of templates used to view a design in an environment. Not only for business cards, let's say a 3D logo on a wall etc. I'm pretty sure these are plugins either for Illustrator or CorelDRAW, but I can't seem to find any. I usually make a 3D perspective of a BC etc in CorelDRAW, but that consumes too much time and they don't always look as good as.
What are these templates exactly and where do I find any to use with my software?
They're called mockups and they are not plugins. Photoshop is what you want for creating mockups or using mockup templates.
Most of the time they are actual studio quality photos of the products (business cards, t-shirts, etc.) like the one in your post, and a layer mask or similar used to apply the design to the object.
Of course it varies depending on the application and the design but there are lots of free ones that might be useful.
A google search of 'graphic design mockups' will help shed some light on the subject.