I did it on n900 terminal (estel image on sd card)
It take some time (1,7MB/s)
But it should be working on PC - dd if=/path/to/file of /dev/sdxx (check number of partition by gparted or sfdisk -l, in my case /dev/sdd4 (same time as n900)

PS: You can check progress of dd by typing in another terminal: "kill -USR1 pid" (you can check it by top)