The path to v4l1compat.so has been changed. So, you should use the command:

LD_PRELOAD=/usr/lib/i386-linux-gnu/libv4l/v4l1compat.so /usr/bin/skype

----open Software Centre and install Ubuntu restricted extras from there.

Once this is done open a Terminal and copy and paste the following command

sudo gedit /usr/share/applications/skype.desktop
After you have provided your password a text editor will open. Line 4 should look like this

Exec=skype
Replace with this text

Exec=bash -c 'LD_PRELOAD=/usr/lib/i386-linux-gnu/libv4l/v4l1compat.so skype'
Save and exit the text editor and close the terminal. Now you can open Skype and test your webcam via 'options' then 'video devices'

http://askubuntu.com/questions/126765/skype-video-not-working-after-upgrade-from-11-10-to-12-04