kapusta-
If I understand you correctly, you want info on how to speed up your downloads, not speed up your actual computer.
In that case, most of my earlier questions are not nogeah, because computer speed and download speed are two different issues.
Also, if you regularly plan on downloading huge files (i.e. movies) you may be among the minority of people who should spend the extra $$$ and get a cable modem rather than DSL.
Does this address / answer your question?