Just to let everyone know, Disk Copy burns Toast image files. I'd assume it mounts them as well, although I can't currently test that.
[Editor's note: I thought I recalled reading somewhere that, with the OS X version of Toast, Roxio had dropped their proprietary format. Does anyone have any solid information on this?]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20020226014425461