I had never heard of this site until a competition came up this morning. However it is a great idea for photographers who may not know the lens or camera equipment they want to use. Through Borrow lenses you can both photographic and video equipment to suit any shoot or need.
This is a great way to immerse yourself in new styles of photography without the initial costs, if you like the lens or body you can then choose to buy it.
So enjoy your photography, mix it up, its about what you see through your camera that creates a photo.