I often use dd to copy large files or make images from hard drives. It's annoying to watch something without any progress indicator, so I use the little known kill switch on dd.
From the man page:
Sending a USR1 signal to a running ‘dd’ process makes it print I/O statistics to standard error and then resume copying.
$ dd if=/dev/zero of=/dev/null& pid=$!
$ kill -USR1 $pid; sleep 1; kill $pid