Send URL to your Kindle using Kindle It via Hatena Bookmark Web Hook (Japanese).
First, create new app on Heroku.
$ git clone git://github.com/kyanny/send-to-kindle-it-via-hatena-bookmark-web-hook.git
$ cd send-to-kindle-it-via-hatena-bookmark-web-hook
$ heroku apps:create
$ heroku config:add KINDLE_EMAIL_LOCAL_PART=kyanny (set your Kindle email local part)
$ heroku config:add KINDLE_EMAIL_DOMAIN=free.kindle.com (If you want to get document via 3G, replace to kindle.com)
$ git push heroku master
Second, enable Hatena Bookmark Web Hook. Goto 外部サイト連携 - Web Hook (開発者さま向け, 3つまで登録できます) and enter your app's URL.
Finally, add one more config var.
$ heroku config:add HATENA_BOOKMARK_WEBHOOK_KEY=XXXX