Might be worth mentioning, dd uses an incredibly small bit size by default, which makes the speed very very slow when copying.
To fix this, specify a larger bit size. I use roughly 4 MB and that sped up the transfer by about 15 times!
Also, if you want to see the progress of dd once it has already started running, run the following command in a seperate terminal window:
sudo dd if=FROM of=TO bs=4194304
watch -n 10 killall -USR1 dd
You'll now see when you switch back to the window / virtual terminal that dd is running in that it has started to output how much data it has transfered. Really useful.