Downloading torrents is always a good way to churn bandwidth. My favourite client is uTorrent, but Vuze will often be a better cross-platform solution. Of course, for the ocasional rare download the Opera browser will do a fantastic job as an all-in-one (web, email, news, torrent, irc, WOW!)
One way to preserve your download quota is through using local peers, you can do this via these handy
IP addresses for Australian peer networks (eg: WAIX).
Another alternative is to use something like Vivaldi (paper includes pseudo-code). Bittorrent clients normally choose the highest bandwidth connection over lower-latency (ie: closer) connections. Ono is another option/plugin for Vuze that will let you prefer closer clients.
The algorithms are quite straight foward although computationally intensive. A good choice for GPGPU?