using dd for cloning

[elmo]

I have just about given up with using various cloning programs in ubuntu 
and have just tried using the ' dd'
command to copy partition to partition

My UBUNTU is on partition sda2 and I'd like to clone it to sdc1 , a ext3 
formatted partition on an external hard drive.

I tried  running:    dd if=/dev/sda2  of=/dev/sdc1 bs=512

I couldn't see any action except a constantly blinking mark.  I waited 
for a minute or so and there was no change, just a blinking mark. I 
wasn't sure if this indicated that data was being transferred or not.

Can someone get me on the right track with the ' dd ' command?

elmo