An excellent forum post about loose leash walking...

...and dog training in general:

http://pets.groups.yahoo.com/group/Click_To_Calm_List/message/7842

Re: [Click_To_Calm_List] Re: leash anxiety

Hi, I mainly lurk, but this is such an interesting subject, and I do have
strong views....

I had two rescue GSDs, and at 15 months they had never worn a collar let
alone been on a lead, so I had what might be called some interesting
experiences, and at the time, very little positive help. Internet help
mainly consisted of repeating the old and tried methods which I knew and
which hadn't worked for me. For instance, with one dog I tried the stop
every time the dog forged ahead method. Fine, apart from the fact that a
five minute walk took three quarters of an hour, we could do that, but she
couldn't connect the stop start with a continuous walk, no way. Head
harness? Just sat down and refused to move....

Eventually I succeeded, but whether it was just age, experience, or one of
the methods I used, I couldn't say. I believe there is a way for every dog,
but considering the pairing of any dog and any human is a pairing of two
unique beings, it can take time to find what works for you. Clicker
training came along just a tad too late for our early days....

One thing I believe many people forget, or do not heed, is that it is
counter-productive to start using a method if you can't use it each and
every time. Look at the number of dogs in classes that behave beautifully
to heel in class and then pull like a demon on the way out to the car....
IMO we are taught to watch our dogs for the response we want, and click and
treat. What some people forget is that dogs watch us, and wait for the
response THEY want - if they get it once - then it can take a long time for
the hope to fade it won't happen again.

I have a theory about learning anything. Before you start, look at the line
of books on the subject in the book shop. How many are there claiming the
quick way, the easy way, etc. If there are plenty then there is NO quick or
easy way, because you wouldn't need a book to tell you. I have yet to find
a book titled the Easy, Quick way to learn to love Chocolate....

So, IMO we often create or exacerbate the situation by our own anxieties -
which travel down the lead like an electric current. It isn't easy to relax
with a pulling dog, but I think, whatever method works for you in the long
run, the first thing is to relax, think about it, and say to the dog, we are
going to get through this together, you and I...

Just my thoughts
Brenda