$ hdiutil convert -format UDRW -o Desktop/usb.img /Users/oreore/Downloads/debian-6.0.5-i386-CD-1.iso 

Master Boot Record（MBR：0） を読み込み中...

Debian 6.0.5 i386 1             （Apple_ISO：1） を読み込み中...

（Windows_NTFS_Hidden：2） を読み込み中...

...............................................................................

経過時間： 8.422s

速度：76.8M バイト／秒

節約率：0.0%

created: /Users/oreore/Desktop/usb.img.dmg

$ mount

/dev/disk0s2 on / (hfs, local, journaled)

devfs on /dev (devfs, local, nobrowse)

/dev/disk1s2 on /Volumes/Lion (hfs, local, journaled)

/dev/disk2s2 on /Volumes/Lion3 (hfs, local, journaled)

map -hosts on /net (autofs, nosuid, automounted, nobrowse)

map auto_home on /home (autofs, automounted, nobrowse)

/dev/disk3s1 on /Volumes/UNTITLED (msdos, local, nodev, nosuid, noowners)

$ sudo diskutil umountDisk /dev/disk3

Password:ユーザーのpassword

Unmount of all volumes on disk3 was successful

$ sudo dd if=Desktop/usb.img.dmg of=/dev/disk3 bs=1m

647+0 records in

647+0 records out

678428672 bytes transferred in 903.324871 secs (751035 bytes/sec)