StarDestroyer.Net BBS

My housemates tend to be heavy downloaders and suck up all the bandwidth. I'm looking at any possible solutions that could effectively provide QoS or bandwidth throttling to their PCs. Our connection is 1500kb, so what I'd like is to essentially split that into 500kb for each person, based on the MAC or IP, etc, of the machine, not to worried about other things like smartphones, etc. I have a spare PC that can be used as a firewall. I've looked briefly at IPCop, but not entirely sure if it'll do what I'm looking at. Has anyone here run into a similar situation or have any suggestions?

You could try one of the BSD firewalls such as m0n0wall or pfsense. Both have QOS, and while I can't claim I understand it, pfsense keeps my voip phone system up and working even while using bittorrent. If all you want is a simple firewall, m0n0wall is the simpler of the two to setup and use. I do believe its QOS setup is simpler as well.

Both Zentyal and ClearOS support sophisticated filtering - you can have the system deprioritize BitTorrent traffic (or, for example, prioritize VoIP). They also have shiny web interfaces.

Your internet connected goes through a router, doesn't it? Even the cheap routers you get from the telcos kann do traffic shaping.