Google Reader now has a nice "Send To" feature to share links to various services like Facebook, Twitter, or Instapaper. One draw back I found is not having the source included with the link. So here's a quick work around I put together for sharing links to Twitter:
In Google Reader click on "Settings", then the "Send To" tab. Add click on the "Create a custom link" link near the bottom.
Add this in the URL field:
When you want to share a link, click on the "Send To" button in the main reader.
This will open up your browser to Twitter with the text already in your status field. Just hit "Update".
Hat tip to: Google Operating System: Google Reader's "Send to" Feature