This one is fairly new so you'll be forgiven for not realizing it was there. However, Google has begun rolling out some improvements to search on Android. For starters, you've always been able to trigger voice search in Google Now with the "Ok, Google" hot word. Now, that works even when you're looking at search results.
So, let's say you want to know who's playing second fiddle to Clark Gregg in that new Marvel show. "Ok, Google. Who plays in Agents of SHIELD?" Google will reply with a scrollable list of actors. Now you're curious when you can watch it. "Ok, Google. When does it come on?" Google knows from your previous search that "it" refers to the show "Agents of SHIELD" and will search for what you're looking for. Being able to continue using voice actions without touching the phone is an added bonus.