Have started to experiment with backwards running as part of an interval training session - I go to a local track where there isn't much to bump into! Too early to say whether it is having any benefit but it does feel right - it requires you to engage your core muscles and to land on your forefoot.
Quite surprised at the amount of vitriol from some of the critics on here - horses for courses I guess.
I have found the ideas in Chi running to be really helpful to me - I run faster and recover faster than before - but I found it works best if you make the changes gradually and don't do make any drastic adjustments. It does require patience though.
Re: tutors, I can also recommend Michelle Muldoon - I went on a course she ran on Chi a couple of years ago and was v. impressed.
I agree that the most important thing is to make sure you pick a shoe that is right for your own individual biodynamics. It is also important to get advice from a reputable specialist - Run and Become are my personal favourite.
However re: minimal running shoes, I wanted them not because my old Asics 1150's gave me any injury problems, but because I wanted to become a better runner. That said, I think there is more to improving running style than just changing shoes; for me practicing Chi Running has made the greatest difference.