I use the cli-tool mmsclient that comes with
ASFRecorderX for Windows Media streams, and for Realmedia streams I use the cli mplayer with the -dumpstream command.
I don't know of any way to capture streaming Quicktime that doesn't involve recording screen activity, but if that sounds like your thing, check out
Snapz Pro.
Edit: Another option is to acquire VirtualPC to run your old stream recorder.