The only way you should ever have to pay the "rack rate" is when you are in a blizzard, the next-closest hotel is 50 miles away, and you have no choice but to stop for the night at the hotel you are in front of.
Even if you call them on your cell phone from the hotel parking lot to ask for a room price, you'll get a better deal than the rack rate. Do you have an AAA card? Always ask for the AAA rate if you have no other discount options available. Nine of out ten times it will get you some break, unless you're going somewhere that's going to be sold out for some event.