Tell them to get Kazaa lite K++ ~~~ no spyware.
But if they were my roomates I would just beat their asses for screwing up my ping ... why do they even leave it running... why not just download the songs they want and exit... if I was you and if I was the one paying for it, I would tell them to AT LEAST disable uploading to others, that is most likely what is creating a bottleneck on your connection.
If worse comes to worse... I would unplug their shit from the router while I was online... HOMEY DON'T PLAY DAT! ~~~ damn slackers!
- Damon