Originally Posted by Yachtzee
Also, if you already have cable, in many cases they can use the existing cables and such, so they aren't drilling new holes in the side of the building.
This is 100% true. Once the cable lines are attached to the structure, they no longer belong to the cable company. I am running 6 lines into the house and only one of them was run new by Dtv installers. I just hooked my multiswitch up to the existing cable lines and they worked just fine.
As far as your landlord letting you put up a dish, here is the law as set forth by the FCC: