reading raster data

Has anyone got any experience with getting GRASS to read raster data other
than GRASS raster data without converting the data first ?

src/libes/gis is the directory where the reading is actually done.
There are many functions there that assume what the format of the raster
file is. So it would requiere changing all read/write/open/close routines.

Boris Livshitz
Postgres Group
UC-Berkeley