I used to think that everybody already knew that they might get an employee discount from their carriers. That was until I mentioned it to a friend who had no clue. Turns out he got a 9% alumni discount from his college for his Verizon wireless bill!
So I thought I would mention it again. Many employers have deals with carriers to give their employees discounts on wireless service. For example, AT&T is pretty liberal with theirs and gives many companies a 5% or 6% employee discount without a fight. A friend of mine who works at one of the big four accounting firms gets 25% off his AT&T bill!
With that said I thought it would be prudent to mention these discounts again. Many companies offer them along with some colleges, associations, alumni programs and such.
You can try to check if you are eligible for a discount using the links or phone numbers below that I got from the Consumerist. Personally I think it is a better idea to just ask your HR or group representative but this can also work.