Today I had the great pleasure of deleting a huge chunk of old code from my application. Using git it's surprisingly easy to figure out exactly how much code:

 
git checkout -b deletion_task

# ... delete lots of code...
# ... time passes...

git add -i
git commit
git co master
FILES_DELETED=`git diff --summary master deletion_task | grep "^ delete" | wc -l`
LINES_DELETED=`git diff --summary master deletion_task | grep "^ delete" | awk '{ print $4 }' | xargs cat | wc -l`
echo -e "$FILES_DELETED files deleted.\n$LINES_DELETED lines deleted."