looking in the obvious place worked, but useful incantations for similar tasks (though rather noisy on the VIM source) shown below
# search for things of the form <foobar@atleast.twopieces>
# ignoring binary files, recursively
grep -IRn "<.\+@.\+\..\+>" *
# same as above, but show only files that match
# the extra option is a lowercase L
grep -IRn -l "<.\+@.\+\..\+>" *
# OUCH! that's still noisy, people like to put emails in source files
# lets just look in the root
grep -In "<.\+@.\+\..\+>" *
I found the info command useful to get a better understanding. I'm on Ubuntu 9.10
info 'ID database' # good info
cd vim # same dir cloned from googlecode
mkid # makes a file 'ID' in this directory
fnid *.c # shows c files
fid src/if_python.c # shows identifiers in the C file
lid python_buffer_free # shows files with python_buffer_free in them
