Skype for Mac OS X
History
You can view a list of all your calls, file transfers and voicemail messages by clicking the ”History“ button.

A new window will appear with a list of all your calls and the duration of each call. You can delete your history by clicking the “Clear history” button in the left corner of the window.
To view chat history for a specific contact, select the contact from your Contact List and go to: “Contacts” > “View Chat History”. A browser window will open showing your previous chat sessions with the selected contact.
You can also view a list of all your SkypeOut calls and the cost for each call by clicking the amount of credit remaining and then “Visit account page”.
A browser window will appear and you will be asked to enter your password and Skype Name to sign in to your account page. You will find a list of all your SkypeOut calls by clicking the “Calls & SMS history” link.
You can also access this information by selecting “Go to My Account Page” from the “Account” menu.