(The URL's wrong, should be
http://pit.deepbit.net:8332)
I just tried with the following parameters, and it works perfectly:
cgminer -p pwd -o http://pit.deepbit.net:8332 -u email@re.ss_worker
If it doesn't for you, try adding the -T and -D parameters, that helped me when I misremembered the worker's name just now.