I believe one rule that could work is something like this:

- Indent case labels inside a switch two spaces.
- Indent actual statements inside a switch four spaces.
- In the case where a case label is followed by a block, include the open brace on the same line as the case label and indent the matching close brace only two spaces (but still 4 spaces for the contained statements).

This is precisely the rule that the Google C++ Style Guide uses ( http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml#Loops_and_Switch_Statements ). I think it works well. I support it.