An old friend once told me this, so here's mine.
And now you!
<span class="lastcommit-widget" data-user="your github username"></span> <script src="http://johannilsson.github.com/lastcommit/widget.js"></script>
The code above will, when included on a webpage show and link to the last commit made by the provided user.
It's not smart enough to filter out commits by others in a repository on the users account.
Oh...and it only works for GitHub accounts.
Fork it on GitHub