The idea is simple: "If this, then that." If something being monitored occurs, an action is created. And the site can get especially useful if you tap into its deep repertoire of available options.
Potential Triggers from Ifttt.com
Some Triggers from Twitter on Ifttt.com
At present, If this, then that, or ifttt.com, supports 22 different services and an array of triggers that you can manipulate to gain your attention. For example, you can set up a task that tweets on your behalf when you upload a new photo to Facebook. Simple, right? You can monitor RSS feeds for updates, or watch for tweets from friends of yours that contain specific keywords and get a notice by e-mail, with polls taking place every 15 minutes. It's not quite Pubsubhubbub, but it's not bad either.
Send me an e-mail if it is cold!
Call me if Apple stock goes up!
Stepping outside the world of social notifications, you can watch the real world - getting a text if the temperature outside drops below 45 degrees, or even getting a phone call if a watched stock ticker goes above or below a number you have selected. It's a lot of fun to consider the possibilities, when the many options are laid out.
If you have access to ifttt.com, creating new triggers for actions is simple. First, choose a trigger channel (like Craigslist, Delicious, Google Reader, or Twitter), choose a specific trigger, fill out trigger fields, if any, and select an action channel to carry out the task. Imagine getting a text message if your favorite blogger wrote a post, or getting a phone call if somebody mentioned your ID on Twitter. It's humorous to get creative.
Creating a new Trigger to Tweet my blog posts.
Most of the individual services have triggers themselves for alerting you to saved searches. But the linkage between all the triggers and their action channels is something that could make ifttt.com useful for somebody tired of searching for answers on the Web who wants the data to be pushed to them automatically. I've got tasks all set to keep me informed without my even searching.
Want to get in on their private beta? Sign in here to get on the list. You can find them on Twitter at http://twitter.com/ifttt.