I have an SL Technology NetBook100 and the following line added to alsa-base.conf
options snd-hda-intel model=eeepc-p701
This fixed an issue with the speakers not being muted when the headphones were plugged in.

The microphone works for skype/ekiga, although it does not work for the
"sound recorder" application. I can get sound recorder working if I configure
the "sound capture" setting to "pulseaudio server" in system > preferences > sound
but this will break the mic for skype/ekiga calls.

Machine Specs.
ubuntu 9.0.4 jaunty jackolope
Host bridge: Intel Corporation Mobile 945GME Express Memory Controller Hub (rev 03)
Audio device: Intel Corporation 82801G (ICH7 Family) High Definition Audio Controller (rev 02)
Codec: Realtek ALC662 rev1
ALSA version 1.0.18