I have an Asus WL-520GU router with Tomatousb 1.28. I have a 2TB drive attached to it through the USB port. I set the router up for "yes, authentication required" in filesharing and put in a username and password. I used Tomato because I read that it had better USB support - no idea if that is true.
On my computer I have Maverick installed.
I put the following line in my fstab file:
//192.168.1.1/share /MountPoint cifs rw,nosuid,nodev,default_permissions,uid=1000,gid=1000,umask=002,username=unamefromrouter,password=pwfromrouter
This lets the main user create/delete and all others read. Not totally sure what packages I had to install to make cifs available (smbclient maybe?). I use luckybackup to backup to it by just pointing to the MountPoint folder. It works pretty good except sometimes it will gag if I try to watch a movie while running a backup. I can actually play movie iso files directly from it with VLC(but occasional stutter if using wireless).