sudo apt-get install cheese guvcview libv4l-0:i386 libv4lconvert0:i386
Skype is 32bit application that does express fully express it dependencies on a 64bit platform. Your webcam may not be detected even if it is usable in other native apps. For some native apps and the missing 32bit libraries on 64bit Ubuntu run:
The efficiency of affinity with shared nothing.
Nicely summarises Linux performance observation commands.