Record mac screen + audio + skype call?
You can choose to record using the quicktime player if you also have sound flower installed, this will record any application audio (you would have to test to see if if captures both the incoming and outgoing sounds via Skype)

You can find Soundflower here.

When installed start a screen recording in quicktime then click on the down arrow as seen below and choose Soundflower



There are a number of paid applications that will do sound and screen recording if you want more control :-

iShowu -- http://www.shinywhitebox.com/ishowu

Camptasia  -- http://www.techsmith.com/camtasia.html

Voila -- http://www.globaldelight.com/voila/