While reading Slashdot [4] I came across a reference to homebrewing your own DSL connection. In theory, it's simple enough—you order an unconditioned copper pair from the phone company between the two points you want connected (and that will run you about $20/month), then you get the actual DSL equipment needed for either end, plug it in, and bam! Instant DSL connection.
Of course, that's theory. Here in The Real World things are much, much more complicated than that. It seems you have to check with your state (and possibly Federal) regulations for the type of copper lines you need; it also helps to know the lingo (or depending upon the phone company, the part number) and heaven help you if the Phone Cops, those Boys from Bell, ever find out you're getting DSL on the cheap.
[1] http://www.isp-planet.com/technology/homebrew_dsl.html
[2] http://www.isp-planet.com/technology/homebrew_2.html