Relative sizes / distances between stars and galaxies

Hi Chaps,

I came across a reference a while back (I forget where) which said that the
average distances between stars is much greater in proportion to their size than
is the distance between galaxies in proportion to _their_ size. I'm interested
to find out what are the actual average distances between stars, and similarly
for galaxies, and also the mean size of stars and the mean size of galaxies ?

Thanks,

--
Boo