Mac: OS X Yosemite brought new functionality to Spotlight, but it's still a little lacking. Flashlight is an app still in early alpha that adds some handy new features.
With Flashlight, you can instantly pull up the weather, do full Google searches, Wolfram Alpha searches, and even enter Terminal commands directly from Spotlight. At a glance, it makes Spotlight yet a little bit more like Alfred, although still not quite as powerful. Flashlight's early in the development process, but you can still try it out for yourself for free. The Google searches alone make it worthwhile.