when i try and open the following in nautilus:
smb://foobar/shared/file.xls

i get the following error:
"Gnumeric" can't open "file.xls" because "Gnumeric" can't access files
at "smb" locations.  No other applications are available to view this
file.  If you copy this file onto your computer, you may be able to open
it.

if the configured viewer/application associated with a given filetype
doesn't support "smb" locations, nautilus should copy this file locally and
execute the app with the local file.

i realize there might be some problems/trade-offs (nautilus doesn't know
when to get rid of the tempfile, the local file might be read-only since
there's no real file locking on the actual file, etc). 

thoughts?