For my galaxy project (see http://blenderartists.org/forum/showthread.php?p=1689943#post1689943 ), I made a script which takes all vertices in the selected mesh and rearranges them (because I don’t know how to add vertices in a galaxy-like shape. The code is based on
http://www.gamedev.net/reference/articles/article1337.asp
but improved further.
The files can be found at bitbucket
http://bitbucket.org/quiark/galaxy/src
Hope you find it useful!