The following news talk about a technology, which will add up the internet speed of several lines to increase the total download speed. This news was appeared in 5 yeas before, so I believe there should be some improved technology at this time.
please check..
http://www.nytimes.com/2006/01/16/technology/16mushroom.html

also check this

http://blog.seattlepi.com/venture/archives/101123.asp

But anyway I guess this topic poster is talking about simple sharing of a single line with multiple users.