I'd like to be able to send all the contributors working on a project a message whenever a commit is made. This way, everyone sees the contribution, and hopefully someone will take a look and spot bugs and whatnot. Furthermore, it provides our bosses with a nice and simple, if a little incomprehensible, way to get an idea of how the project is progressing.
We're using Mercurial right now.
Have you tried the notify extension? This commit hook can send out email notifications.
The easiest way would be to incorporate this into your CI process if you had one (i.e. add a task to your build to spam the group).
That said, I would highly recommend you NOT do something like this.
First, without some defined process of who is to review what, this will just become noise and will likely get ignored.
Second, email makes for a poor medium to review code. By reviewing the code in an editor, the reviewer is free to use the full power of the IDE to navigate around the code.
Third, motion doesn't equal progress. Showing management that things are happening doesn't mean progress is being made.
If you want a way for management to see progress being made, consider using a task board that reflect backlog items, in progress items, items completed, etc.
If you want better quality control, use agile processes like TDD and pairing, and self-organize around ability & experience (which is to say that the better developers are mentoring the weaker developers).
If you want feedback about when bugs are introduced, use continuous integration.