I've been poking around lately trying to find a solution to the problem of excessive bandwidth usage. Now, in Windows I simply use DU Super Controller to limit the bandwidth a certain program can use, but I have failed to find an alternative for Linux. If anyone can assist me, I would greatly appreciate it. It may or may not help, but the specific applications I want to limit are Up2date (I'm using Fedora Core 3 and it uses that for updating) and Azureus. I'm not too familiar with the network underworkings of Linux so if I can do something with whatever is already on my machine, you may want to be extremely specific. Thanks.

That can be done with iptables and iproute2, but setting that up isn't trivial at all:
http://www.knowplace.org/shaper/
http://lartc.org/

You can find more stuff serching "traffic shaping" on google. Probably there are some (likely comercial) apps that are easier to set up.
Sorry for not being more specific but I've never tried to do that myself

Or you could build an ipcop firewall to put both windows and linux behind and not have to run extra software on your PC to do bandwidth shaping

Well, I don't have enough spare (compatible) parts to build one. I want to be able to browse in Linux, and I dual boot so I don't really need a seperate solution to encompass both operating systems.