Nikos:
> Is there a way to accomplish a 180 deg. rotation using the
> listgeo/geotifcp command line tools?
try saving meta data to a file as detailed in the libGeotiff FAQ, then
tifftopnm | pnmflip | pnmtotiff
and reattaching metadata as shown in the FAQ entry.
http://www.remotesensing.org/geotiff/faq.html#preserve_metadata
Hamish