Here is how to add more computers to blog from with Heroku and Octopress.
On computer 2 (assumes Rails and all dependencies are installed):
First clone your Octopress site. Then cd into the clone, generate, commit and push.
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Now you can manage your Octopress blog from computer 2.
The next day you want to add a post from computer 1. On computer 1, check the name of the remote repository:
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Now you need to fetch the files from the heroku repo and merge them.
And all is set to manage your blog from computer 1.