Tumblr Trick - short urls
I found out how you can grab the short “http://tumblr.com/sfsfsfsf” style URL for your tumblr post without auto-posting to Twitter (which is the only place that the URL is exposed in the UI). Turns out it’s sent along with every request in a “Link” header following the Short URL Autodiscovery spec. To grab it, from Chrome or Safari fire up the Developer console and click “Enable Resource Tracking”. Then hit the direct URL for your post and look in the Response Headers section:
Pretty handy.