In Snow Leopard, when opening Freehand files, the app crashes. The fix is to use the Freehand Clip Art Viewer, which is located in the application's own folder. If you browse the hard drive with this utility, then you will see thumbnails of your files -- simply double-click on them to open.
Adobe tech support were of no help at all, as they said Freehand has been upgraded to Illustrator CS4. Hope this helps other frustrated Freehand users.
[robg adds: As I don't have Freehand, I can't test this one, or even confirm the problem.]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20100114145539844