Will compare a fork of a project with the original to get a single diff of what the fork has done.

gistfile1.sh

#!/bin/sh
# Provides a way to compare a fork against the original it is based
# on so you can get a general idea of what is in a fork.
#
#   git-fork-compare <original> <fork>

TMP_GIT=`mktemp -d`;
rmdir $TMP_GIT;
git clone -q $2 $TMP_GIT;
cd $TMP_GIT;
git remote add orig $1;
git fetch -q orig > /dev/null 2>&1;
git diff orig/master...master;
rm -rf $TMP_GIT;