I want to look at how my code base has grown over time. GitHub has a nice +/- display along the list of checkins which gives a sense of this. Is there something similar I can use with my Google Code hosted repo or offline?
There are a few options natively in Git to get data about the changes.

git log --stat will show the amount each file was changed.

git whatchanged gives some detail into the files that were modified.

git diff --stat <sha1> <sha2> gives the files and the amount of changes between two commits.

There are many other blogs that give various formatted logs.  A google search can point you at these.  Also doing git log --help will give the various options for formatting the history of your repo.  Git has the ability to give you quite a bit of data through the various command line log options (filtering by author, file, etc).
