I read a tutorial on this site: Ubuntu
It is about mounting networkshares permanently is FSTAB.
For me, on a Ubuntu Lucid Lynx or Maverick Meercat machine it was only necessary to add one line is FSTAB: (make sure it is ONE line).
//192.168.2.1/fnd /media/networkdrive cifs username=yourname,password=yourpassword,dmask=777,fmask=777 0 0
This line makes the share read/write for all users. Make sure that /media/networkdrive does excist. (gksu nautilus in a terminal and create a new folder in /media with this very name)
All the files needed were already available. It too works on my laptop with a WIFI connection when the WIFI is available for all users.
The tutorial gives extra information about security, but that's only needed when other people have acces to your fstab file, since they can read the password to your share in it. Use the credential file if security might be an issue though!
A manual of rsync can be found here.