Editing functions.php and other such nicities

Last night I saw a post by Sue who mentioned several places where functions and such had to be edited in order to take advantage of some or all of the Supporter features. This seemed to include theme functions to make them WPMU friendly.

Today I saw a post from Aaron, I think, where he mentioned editing something, for a very similar purpose.

Is there a list somewhere of all the things that need editing? Mainly because I, being the old, forgetful, and slovenly fogey that I am, haven't edited anything except footer.php, and that was for my own purposes.