There was a rumor a coupla weeks ago, when I had difficulty in installing SPD on a standalone, no internet system (gasp!), that MS would make SharePoint Designer 2007 free on April 1. Well, considering the date, I was semi-skeptical, but optimistic to the point in suspending my attempts to check.

On April 1, you still had to buy it. On April 2, it was indeed, free. I have now installed on the disconnected system with no issues.

You can get it here.