In Internet Explorer you have the drop-down menu option called "Page" (located below the address bar, on the right-hand side). In the options listed you can "Open FTP side in Windows Explorer".
I cannot seem to locate a similar option within Firefox 4.0.
Guidance and suggestions welcome. Thanks.
You can look at:
Thank you for your help! I've started using FireFTP, integrated for use within the browser is very helpful