I found this little Sinatra app a couple of days ago and have now set up it to automatically deploy this Jekyll site to Heroku when I push the repository to my Github account. It receives a post from Github via the post-receive service hook, fetches the updates and push them to Heroku.
I have made some changes to the app, so use my fork until the pull requests has been merged. My fork adds support for private repositories and makes it run smoothly on just one free Heroku Dyno.
Just follow the instructions in the README and you're done in less than 5 minutes.
I've have switch to a more competent solution for my continuous deployment to Heroku.
Heroku has released their own Github integration.
July 29, 2012