Susan, I agree with you when you say 
<I am not
a big fan of nipple shields.  Maybe this is because I see them abused
and over-used.  They are commonly handed out like candy by busy nurses
who see the shields as prevention and/or treatment for injured nipples.>
In hospitals here in Australia there has been a steady reduction over the years in the length of stay (heading towards the US Managed Care).  Nipple shields are being used before the colostrum has been taken, and before milk is flowing easily.  The rationale for using a nipple shield is often "This baby's hungry ( hasn't been able to nurse effectively) they are going home tomorrow - problem solved!".  Problem may just be put on hold for a couple of days. 
You then describe the way babies and mothers so easily lose faith in each other, and they do get angry:
<The babies that are coming to me on the first or second week pp are so
confused and angry when the mother tries to nurse without them.  It is
one frustrating business for both mother and baby.>
This, in my mind, is often the hardest time.  Babies (and mothers) know instinctively that they are supposed to feel good about going to the breast, and it is only reasonable that they get angry if they are not rewarded for their efforts.
<The only time I
would advise them is when the mom is ready to throw in the towel or as a
last resort for a baby is used to bottles and simply can't latch without
the plastic.  Don't you all see a reduction in milk supply when the
shields are used regularly?>
I agree that nipple shields should be a last resort, and think that probably many of those who have spoken in favour of the shield would agree.  For some mothers a nipple shield is the appropriate intervention that protects the breastfeeding partnership in a way that suits the woman and adequately meets the baby's needs.  But as with most gadgets they have the potential for misuse.
<I call them nipple condoms.  Yuk!  No>
I hadn't thought of them that way before!

My usual management plan for any mother or neonate who tells me that the feeding is not working is pretty simple.
        Attempt correction of positioning and attachment at breast
        Educate and empower the mother to make decisions about what needs to be done
        Initiate processes that will improve attachment at breast (co-bathing, skin contact, and prone baby massage to help stabilise and strengthen the muscles of the baby's jaw and neck)
        Offer advice on simple, low-tech interventions that will ensure baby receives mother's milk every time breastfeeding is attempted.  This includes teaspoon for small volumes, and a cup for larger volumes.  I do not recommend bottles.  I also steer clear of syringes and supplementers.  Most women who have no medical background are uncomfortable with syringes, while we health care professionals see nothing threatening in a syringe.  Disposable syringes were never intended for multiple uses, with milk, and there is a potential for inadequate cleaning.  Teaspoons and cups are non-threatening, easy to clean, non-medical items available in anyone's kitchen.  So I like them.
This has been a bit preachy - sorry.  Perhaps an important issue that we often don't talk about is the trust the woman has in the person who is advising her.  Conflicting advice is probably more damaging than the actual methods used.

Keep up the good work.  
Joy Johnston, Midwife IBCLC 
Melbourne Australia