On the off-chance that you're on a UNIX based system... du -ks * will give a list of all directores (including .) and their size in K (thus -k). If you have the GNU version of du(1), you can s/-k/-h/ to get Human readable output.
Then again you're probably in a Win environment, aren't you?
Yeah, this will be run on a windows box. The network admin here wants to be able to check the size of web folders to make people aren't going over the allowed limit. This came up when we were talking about C++ programming, but I told him I could do it in Perl, but I considered trying to compile the 'du' source on my windows box.