How do I change the link on the logo in the header to go somewhere other than the Homepage?

First, I want to change the link from the logo to the Activity Page. Secondly, I am designing a social network site and they would like the Home Page to be the Activity Page. However, I can't simply keep the Home Page as the Activity Page because that is what shows up to non-members on non-signed in members. I have taken advantage of the two menus for logged in and non-logged in but there are still issues.


Thank you,