Just to prove that it can be done, a pair of Swedish networking specialists have crafted a 40 gigabits-per-second fiber-optic connection for a Stockholm residence. To put that into context, that's almost 14 times faster than the ceiling speed for a T3.
The speed is reached using a new modulation technique that allows the sending of data between two routers placed up to 1,240 miles apart, without any transponders in between, said Hafsteinn Jonsson, head of the Karlstad city network unit, according to this Yahoo News story.
To the extent that such speeds ever become practical, this could start to push the limits of hard-disk desktop space, let alone the amount of RAM needed to manage such a vast data pipe. That said, it still sounds like a fun connection to have in one's basement.