You're right, there are many other dependencies I didn't have. I tried now the -r flag and some dependencies compiled but I stuck again, this time it is the py25-wxpython which doesn't compile giving the attached output.

Looks like port's py25-wxpython package is broken on snow leopard: https://trac.macports.org/ticket/23438

Do you have some experience with that? I tried to get some help directly for the py25-wxpython issue but didn't get anything until now.
Did someone successfully install rviz on snow leopard?

I don't unfortunately, my test machine is on 10.5 still. You could try installing the python 2.6 versions of things and using python_select to choose 2.6 instead of 2.5, but that also may not work.

Josh