My house has an OLD sewer connection. Gotta snake the tubs and sinks(and formerly the kitchen sink and washer connections) so often that I used a hole-saw to remove the cross-shaped bits that would normally hold a plug(and catch a bit of hair).

You'll never guess what never comes out(any more) with our 50ft, 1/2-inch drain auger; Hair. Waxy stuff? Check. Black Goo? Check. Fricken YARN/threads from the washing machine on the other end of the house? Check. We've somehow got it down to where only the tubs need snaked regularly, but still, no hair any more.

I thought the whole house was sharing a 1.5-inch(okay, two inch) connection, then a few months back when there was flooding nearby, this bastard swam up our toilet:

Figure he needed at least a three inch pipe to get through without just getting stuck.