it can work, but the cost will be so great, you probably wouldn't want to do it. IO've read that you need two phone lines, and two modems and then use special software to combine the two modems. Of course, that will still give you only about 90kbps which won't help you. And all the extra cash you'd have to spend....
DSL/Cable is WAY better. I get 1000kbps down/320 up and it costs me only 40CDN (25US)