GIT Log or Commit Monitor
The best would be to use the post-receive hook.
On your repository on the server, you have to put a shell script named 'post-receive' in the .git/hooks directory. This script will be invoked each time something is pushed and it's passed argument via stdin in the form
There are examples scripts provided with recent version of git. Look in:
/usr/share/doc/git-core/contrib/hooks/post-receive-email
On windows, look at the path of your install to find it ...
https://gitmonitor.com
This site has a tool like what you're looking for... I came here trying to find info to see if it's good or not.
There is git monitor which displays popup notifications. It should work in Windows using Growl: https://github.com/spajus/gitmon
I have started an open source project to build a tool that does this. SourceLog is a .NET v4.0 WPF application that monitors version control system change logs. The application uses a plugin model to support multiple version control systems. There are currently plugins for Git, GitHub (via the API), Subversion, Perforce, and TFS 2010.
The application polls each "subscribed" repository for changes and displays a "toast" notification panel when new changes are detected.
The project is hosted on GitHub and the app can be installed via the ClickOnce installer hosted on AppHarbor. There is more information available on my blog.