how do you check deleted history on a playstation 3?

HI,

It's impossible to check deleted log files where stores skype history.

If deleted , and not in the trash, it's gone. And Skype server didn't hold that chat history.

The only way i can see may work is Recovery Tools,

Recover My Files - Data Recovery Software

The email that is connected with the itunes account he has connected to his iphone should send emails Everytime he downloads an app even if its free, its like a reciept. even if you deleted it once and reinstalled it. So check the email and you can see what apps hes downloaded and redownloaded.
As for the safari browser history, no. there's no way you can get it back once deleted.

I don't think you can check the history once you delete it.