I thrilled at a brief remark by psetus back in the "Simplified vs. Diamond Jubilee?" thread, that original Gregg provides notation for vowel sound distinction.
Could any gurus grace us newer-system students with a description of that system, detailed enough for real use? Perhaps a jpeg, even? Be assured this would improve my quality of life significantly!
Incidentally, for any other techies in the group, I think that such a system would move Gregg into candidacy for OCR input on tablet PCs and PDAs (given the initial hurdle of cursively written character sets generally): if vowel signs aren't ambiguous, translation from Gregg outlines to text should operate on the same principle as voice recognition; and that hurdle is being cleared as I write.
For an interesting run at this problem from a slightly different angle, google IBM's SHARK/ATOMIK experiment. At least one of the researcher's papers explicitly compares their system to Pitman and Gregg.
(by routine-sibling for everyone)