If This Then That
I used to have Twitter post automatically whenever I updated my blog or web pages. This suddenly broke and I have been doing it manually for the more "important" posts. Now there is a web site called ifttt.com which stands for If This Then That. It allows you to write simple one line programs to do things like send you an email if the market goes down 400 points or post to Twitter based on an RSS feed or send you an email or SMS if it is going to rain tomorrow.
If This Then That has hooks into Facebook, Twitter, Tumblr, Google Reader and dozens of other sites. You don't have to provide your password. You simply authorize the ifttt app on the site in question and you are good to go. There is even a date and time feature so you can have the app send you a text message as a "wake up call." Very handy.