prickly and hairy!

I have a cactus which has been with us for some time now and it has reached a good 2ft in height. It is a trio of tall 'spikes' which are covered in prickly,hairy needles and they are a * if you catch your hand on them. My wife does this on a regular basis when closing the curtains. I have no means of sending a pic yet,but wondered if anyone had an inkling as to what this type of cactus this might be 

Excellent site Trillium! I think I found my cactus after a bit of searching. It's common name is; Old Man Of The Andes,I wont go into the latin gibberish. Thanks for the site info