fish 2 pacakges (including debs) are already available: http://download.opensuse.org/repositories/home:/siteshwar/ but I would prefer to have an APT conf line too :-)
deb http://download.opensuse.org/repositories/home:/siteshwar/Ub... ./
So for e.g. if you're on Ubuntu 12.10 use :
deb http://download.opensuse.org/repositories/home:/siteshwar/Ub... ./