On the left hand column of Gmail I see my mailbox. Below the list of all my mailboxes, I get a section for "Chat" which lists my recent contacts, and below that, a section for "Invite a Friend".

I'd like to eliminate these. I can press '-' button to collapse them, but they remain visible and I think they reappear uncollapsed the next time you return to Gmail.

Is there a way to permanently delete these items, which I do not want to use, and do not want cluttering up my interface to Gmail?