[wlesieutre]

As far as I can tell, neither Locale or Tasker are competitors to IFTTT. While IFTTT can do things like silence your phone based on location, that's not its selling point.

What IFTTT does is let you set up connections between services. You can trigger actions on other services based on something the phone does (indicate missed calls with Hue light bulbs, automatically share photos taken at a particular location to a flickr album) or take actions on the phone based on input from external services (get a notification when an apartment fitting your criteria shows up on craigslist, or set background photos from your instagram feed).

I don't know of any similar services that hook into anywhere close to IFTTT's variety of inputs or outputs.