git-chrono is like Perforce's Time Lapse View, but it works with git.
You will need Tcl/Tk 8.5 in order to run it. It will not with with 8.4. Tcl/Tk 8.5 is the default on MacOS 10.6 (Snow Leopard) and 10.7 (Lion).
To install, put all the files into a directory, then add that directory to your path. Alternatively, create a symlink to git-chrono in some directory that is already on your path (~/bin perhaps).
git chrono path/to/file