I would love to see a good Mame Diff site to keep track of all the changes necessary for a all the common and not so common changes people make.
examples:
removing ok...
adding analog mame support...
enabling gambling...
they would keep the changes as diff files and source changes (from -> to)
So you could download the latest mame... then you could download the 3 diffs your interested in... and compile!
Seems like it would be VERY useful. If it was easy enought, developers might start submitting their diffs.
(quick note... phil mentioned that he has direct3d code in the windows version of mame for debugging his system22 driver.... would be another great one to add)