I bought an external Sound Blaster Audigy NX2 sound card recently to use with my laptop. Discovered it do everything apart from just working. Think I will spend some time over the coming weeks trying to file bug reports and talk with maintainers of various pieces of the puzzle to see if I can get this working correctly under Linux and GNOME.
The ideal experience would have been to plug in the USB soundcard to the laptop. Get a dialog popping up saying an external soundcard got connected and if I wanted my GNOME applications to use it for default sound output. When I later unplug the soundcard the default would go back to the builtin soundcard of the laptop.

What actually happened is this. Plugged in soundcard. Needed to run Fedora sound config to detect and configure it. Needed to manually edit the gconf key in gstreamer to use the external soundcard or manually configure XMMS to use it. Had no sound. Tried running the gst-mixer, crashed – googled and found others have same problem. Ran alsa-mixer and tried unmuting stuff. After some googling I found the right combination of muting/unmuting to get sound out. Sound now playing but highly distorted, maybe a driver bug or some volume setting that needs adjusting, needs further investigation :). Tried unplugging the USB soundcard, keyboard stopped working….

So I will spend some time figuring out what the problems are and filling bug reports around various places. I think this is a good example of where a non-coder can make a difference as these kind of issues demand that you have the hardware in question, the problem space relates to multiple modules and programs and as such you need to do some investigation and file bugs and work with maintainers across modules to make it work nicely. Filing a bug one place will at best solve a small part of the issue, but the thing here is to start at the bottom then work upwards towards the GUI. Already talked to David Zeuthen and it turns out soundcard detection comes with HAL 0.5 (which will ship with Fedora Core 4) I also bug in Red Hat bugzilla on the issue of borking my keyboard when uplugging USB and one against gnome-media in GNOME bugzilla on the issue of the mixer crashing with the soundcard (seems Ronald might have fixed that one already).