Check this out http://www.dpage.dial.pipex.com/zeltbahn_manual.htm It's got some pretty decent illustrations for 4, 8, & 16 man shelters using the zeltbahn

This http://www.choiquehobbies.com.ar/revista01/html/rev/zeltbhane.htm shows the various ways to wear it and has some actual photos

This site is about the best that I've seen so far http://www.zeltbahn.net/ Very nicely done.

From what I've read a 4 man shelter would be made from 4 zeltbahns but would actually only sleep 2 comfortably or 3 snugly. The last guy would be on sentry. I guess the sentry would just have to suffer if it started raining unless the section managed to scrounge an extra "z" for just that purpose.
Ed