Limit outbound NIC bandwidth?

I want to limit the amount of traffic my NIC is allowed to push out. I have an application that is going to eat a lot of bandwidth and I want to limit it so as not to harm the rest of my network. I've downloaded the WonderShaper and it seems to work pretty good for lower bandwidths (< 1024kbits) but I'm planning on bigger bandwidths. I anticipate using about 15 megabits and the performance with WonderShaper isn't very good at those bandwidths. Does anyone else use any bandwidth limiting tools?