Today it's both a link and a question. Or, perhaps less a question than an idea - we are used, as humans, to the 5 senses, classically divided as Sight, Hearing, Taste, Touch and Smell. This is, however, a short list, for a more thorough list I'll send you (yet again) to Wikipedia.
Now as we all know animals frequently have a different range of senses, dogs, famously, can hear sounds that people cannot, some insects and fish can see in wavelengths that are invisible to us. For a rather complex example try this: http://www.sciencedaily.com/releases/2008/05/080513210456.htm link- a Mantis shrimp that can see not only in UV and Infrared but as well polarized light.
And there are of course those senses - whether real or imagined - whereby we are able to read one anothers thoughts (ESP), or see into the future (Precognition) - but the existence of these is still much debated. But, for an exercise, try to imagine adding a sense - what would it be? Think of how much of our world view and "perception" is colored by our senses, so, if you had to invent a completely new one - not an enhancement of an existing one [like the abiltity to see in UV, which is simply a broader range of vision]- what would it be? And, having invented it, how would it affect your view of the world?