One of the key features in OS X Yosemite and iOS8 is Continuity.
Continuity allows easy handoffs of features between your iPhone, iPad, MacBook, iMac or Mac Pro. Answer a phone call or text message on your laptop. Even if you don’t have wi-fi, you can easily create a wi-fi network from an instantly created hotspot from your phone.
This has always seemed like a somewhat handy feature, but a bit quirky. Sure I guess I’ll answer a call on my computer rather than pulling out my phone?