on an accident i have connect an old USB Lego Cam to the bubba two. Then i have checked some things. At first i have installed the usbutills. Then i have checked /proc/bus/usb/devices and i was surprised about the output.
http://home.kpn.nl/faba00px/bubba/images/usb_cam.png
Ahh, there is no driver installed for the video function. Ok that's clear. I have read more information about usb cam and bubba. But what more interesting is, is the snd-usb-audio driver, aha (tick, tick, ticker, the gear wheels in my haed begun to rotate).
The next idea was to see is the cam listed via the standard lsusb command.
http://home.kpn.nl/faba00px/bubba/images/lsusb_cam.png
Ok, so far so good. My next idea was to install alsa. Ok apt-get -d install alsa. Only donwload the package and check some things. I have learned so many things from gentoo

Ahh i need the alsa-utils package for the mixer. Ok install it and test. Yes, take a look:
http://home.kpn.nl/faba00px/bubba/images/alsa_mixer.png
The next toughts going into the direction for an usb sound stick. What i need more?
Yes a simple audio player with the possibillity to use it via a webinterface. The player is
very simple. MPD player is the answer. Installation was running well. The answer for the
webinterface i have found at http://mpd.wikia.com/wiki/Clients. phpMP is my
favorite, simple and clear. But there are also the concole client mpc and the
other favorite Ampache.
http://home.kpn.nl/faba00px/bubba/images/mpd_setup.png
OK, the sound can't work, because there is only an input (microphone) and no output device.
Now my next idea is to get an USB sound stick. A very nice gadget to test the whole story again.
I will post my experience with sound via usb.