It is a bit anal retentive, but there is sound reasoning behind declaring your variables in the narrowest scope possible. Google's C++ style guide ( http://google-styleguide.googlecode.com/svn/trunk/cppguide.x... ) captures some of them. Another is cache locality of your stack, if you are in a language or project where that matters; by creating space on the stack as late in the game as possible, your stack access pattern tends more to the end of the stack than if you declare everything up top in no particular order. This is a really small micro-optimization though; the main point is that you want to know what type something is and what might have been passed to its constructor, on the screen at the same time as the code that uses it.

Another thought; if there is a mammoth difference between top-of-function and narrowest-scope-possible, that suggests that you may have very large functions, and might consider refactoring so that the difference between your method and his is small?