help: loading binary image data into memory

[rixdelei]

Hi there!
Tried successfully downloading data into memory from internet using the 
urllib module like this:
...
import urllib
import cStringIO

url_file = urllib.urlopen(url)
img = cStringIO.StringIO(url_file.read())
...
Was wondering HOW could I accomplish the same results using the ftplib 
module
-> retrbinary( command, callback[, maxblocksize[, rest]])
WITHOUT saving any information to the disk;

Will appreciate your comments,
TIA+BRGDS