Here is how.
First, be sure your underlying operating system is correctly configured to allow you to do that. I'll show as example how I configured my Debian system.
Your current user needs to have the permissions to mount the volume(s), this is usually done by being part of the correct group. For Debian we find cdrom and floppy as ready groups
The predefined mount-point for the cdrom is /mnt/cdrom, since I usually handle with USB sticks I added a mount point for it:
$ ls -l /media/
lrwxrwxrwx 1 root root 6 Jan 1 1970 cdrom -> cdrom0
drwxr-xr-x 2 root root 4096 Jan 1 1970 cdrom0
drwxr-xr-x 2 root root 4096 Nov 27 14:01 usb
Now, let's add the correct lines to /etc/fstab for our usb entry. The cdrom entry is usually already configured by Debian.
/dev/hdc /media/cdrom0 udf,iso9660 user,noauto 0 0
/dev/sdb /media/usb auto defaults,users 0 0
I auto shall determine the file system automagically, while users allows for user permissions for the mounted files. You can check if everything is configured fine if you can "mount" from the command line with your current user.
Then open SystemPreferences and configure the managed paths as shown here:
|SystemPreferences - Mount points|
Now, in GWorkspace we can select Check for disks under the Tools menu.
|GWorkspace - check for disks|
|Usb stick contents|
If all options are set correctly as suggested, the volume is readable, writable as you can check with the Attributes Inspector. Also we can open the .zip file with Zipper easily.
|Zipper and Attributes|
To unmount a volume, just drag its icon to the Recycle Bin.