Bandwidth limiter

I need a bandwidth limiter for windows that's able to limit the upstream
transfer rate of individual applications.

Blizzard in their infinate wisdom use a custom Bittorrent client where you
can't restrict the upstream traffic. It just starts flooding until your
upstream is saturated leading to very poor download speeds and an unusual
net connection. I have no problem with my download taking longer. I just
want to be able to use the rest of my bandwidth

I'm currently using a demo of some pay software but freeware would be
better.

Does anyone have any suggestions I could try?