on e.g. Debian you have to install

aptitude install sshfs

edit /etc/fstab and add the line

sshfs#user@123.123.123.123:/what/ever/remote/	/where/you/wish/local/	fuse	uid=1003,gid=100,umask=0,allow_other,_netdev,ro		0	0

or directly in shell:

sshfs user@123.123.123.123:/what/ever/remote/ /where/you/wish/local/ -o idmap=user -o uid=1000 -o gid=100 -o umask=0 -o allow_other -o ro