Under UBB 5.4x there was a mod using cookies to change the 'front page' display to only show forums you specifically wanted to see. It was called 'My Favourites' or something.
Anyway I don't want to propose something like that for v6.3, however I do have a similar/easier idea.
Add an extra menu item at the top called 'Favourites', you could add a list of the forms you most like to visit by forum number (extra member field required) and list them down.
Then regular visitors could link to that page directly and it'd be like replacing the front page, only separate? Anybody keen?