I have been using skype in and out on windows for a few months now and I am really impressed by how well it works. I bought a Logitech USB headset to use with Skype and it also works very well. Unfortunately, when I plugged it into my Linux box, it didn’t work. I was able to select the headset as the I/O device in Skype, but Skype was not able to hear me. Using alsamixer -c 1 showed that ALSA recognized the headset and that the mic gain was turned all the way down. All I needed to do was turn the mic gain up and everything works fine.
If you are considering Skype on Linux, Skype 1.4 with Debian testing and the Logitech 350 USB headset will work.