YOU'RE SICK!  WHY WOULD YOU DO THAT!
The things people have against teenagers.
Cholin, remember that just because YOU are a teenager, doesn't mean that you won't think of doing stuff to YOUR teenagers that seem ridiculously unfair.
Myself, I have one of those "plug in the base, and connect up to 5 handsets" kinda phones.  If my kids don't put the phones back on the rechargers, I take the batteries out when I find it again, and they have to use the speakerphone in the base.  Talking to your girlfriend when the whole house can hear your conversation has a remarkable ability to make otherwise "forgetful" children remember the most basic of things 

There was talk of me buying an actual pay phone for the house, since my wife and I have cell phones we use almost exclusively.  My kids seemed to get the message that having a phone they don't have to pay for is a priveledge they enjoy and by following a few simple guidelines, can continue to enjoy.