You might have already heard this, but SharePoint Designer 2007 is now free to download and use.  In the future Expression Web will support both web sites and SharePoint sites all in one.

For more questions and answers: http://office.microsoft.com/en-us/sharepointdesigner/HA103607621033.aspx

To directly download SharePoint Designer go here: http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=baa3ad86-bfc1-4bd4-9812-d9e710d44f42