Rails - Nov 2006 - <label for=..." /> best practice?

I see a number of code samples on the list lately using <label
for="..." /> and this is a new construct to me.  I see what it
does,
but I''m certainly no designer and was wondering if someone could walk
me through when to use it vs. the "old style" of just putting text
where you need it, and advantages of using it vs. not.

Thanks

-- 
Voluminous documentation is part of the problem, not part of the
solution. -- Tom DeMarco