genext2fs generates an ext2 filesystem as a normal (non-root) user. It does not require you to mount the image file to copy files on it, nor does it require that you become the superuser to make device nodes.
http://genext2fs.sourceforge.net/
Please use the genext2fs-devel@lists.sourceforge.net mailing list to contact the developers and/or report bugs.
See the included INSTALL file for instructions on installing genext2fs.