After performing the steps in my
sticky thread and then installing updates, Office 2008, and a few other small utilities, and then letting Entourage cache all 600+ MB of mail from my Exchange Server and copying over some photos and such, I am down to around 41 GB free. My music (35 GB) and movies (27 GB) are ALL stored on my Mac Pro and accessed wirelessly through Apple File Sharing, so I don't have to eat up my disk space with media files.
I still need to install Macromedia Studio 8 and whatever image-editing software I get. That'll use up a few more GB of space. Should have way more than I need left over to copy over all of the files I use to design and manage web sites.