netcat

without compression

# receiver
nc -l -p 1234 > out.file
 
# sender
nc -w 3 [destination] 1234 < out.file

with compression

# receiver 
nc -l -p 1234 | uncompress -c | tar xvfp -
 
# snder
tar cfp - /some/dir | compress -c | nc -w 3 [destination] 1234

transfer disk image

On the sender end run,
dd if=/dev/hda3 | gzip -9 | nc -l 3333
 
# receiver
nc [destination] 3333 | pv -b > hdImage.img.gz