The system maintains a list of currently mounted file systems.

# To mount / partition as read-write in repair mode:
mount -o remount,rw /

# To mount Usb disk as user writable:
mount -o uid=username,gid=usergroup /dev/sdx /mnt/xxx

# Currently mounted filesystems in nice layout
mount | column -t

# Mount a temporary ram partition
mount -t tmpfs tmpfs /mnt -o size=1024m

# Mount a .iso file
mount /path/to/file.iso /mnt/cdrom -oloop
mount -o loop -t iso9660 my.iso /mnt/something

# Mount a Windows share on the local network with user rights and use a specific samba user
sudo mount -t cifs -o user,username="samba username" //$ip_or_host/$sharename /mnt

# To mount a remote NFS directory
mount -t nfs example.com:/remote/example/dir /local/example/dir