There are 3 things you can do:
1) Press Alt+D. This will focus the address bar and make it show the path as text.
2) Install my program
Classic Shell. It has a feature to disable the breadcrumbs.
3) Install
BreadCrumbKiller. It is much smaller than Classic Shell, but its implementation is not as polished and has some bugs.
One more thing. After you disable the breadcrumbs, you will lose the ability to go to the parent folder (since that's one of the features of the breadcrumbs). So I would recommend you try Classic Shell first, because it adds a button to go up one level (among other features).
I myself like the breadcrumbs. Even though I wrote a feature to disable them, I'm not using it
P.S. One more thing - another feature of Classic Shell is to show the path in the title bar. So if you just want to
see the path all the time, that may be enough for you.