Basically what this is would be a category at the very top of the index page that would say, "My Favorite Boards," inside would be all boards you look at often (and in all of the boards there would be a link allowing you to make it your favorite).
This would be great because of the fact that it's a real pain scrolling through the index looking for a particular board.
I know for a fact that it isn't hard to make, being that I've done it myself (for different forum software) in just minutes.
So it would be a pretty cool feature to see implemented (and very convenient upon that).