I just updated to Android SDK-r07 and find out that I don’t have hierarchy-viewer tool anymore, what a nice surprise 
I know this program is stored in hierarchyviewer.jar so just created the hv.bat in tools directory with just
java -Xmx512m -jar ./lib/hierarchyviewer.jar
.. and it works for me.
Another way – is to download Android-SDK-r06 and take hierarchyviewer.bat from it. Still don’t know how it happens that Android-SDK-r07 miss that great tool launcher
For those who don’t know nothing about that great tool, I recommend to take a look at article about layout-efficiency in android and about layout-optimization – and start using and in your layouts. And of course spend some time exploring your view-s in HierarchyViewer.
