just downloading files from websites. I am not a fan of speedtests though, comcast has this speedboost or some shit that ups the speed at first then goes down thru the download. Speedtests are fairly inaccurate with these, but I will try one when I get home from work.
I usually download xp service pack 2 from microsoft to determine how fast my internet is. Their servers are fast and consistent, I am normally over 1mb down from their thru the whole download.