It feels like I've waited half my life for this: someone has modded a gravity gun into Grand Theft Auto 5.
Why not pick up and lob a lorry? How about tossing a truck? You-hoo, civilian - where do you think you're going?
Mods aren't officially supported in Grand Theft Auto 5 on PC, but what there is can be found on GTA5-Mods.com.
Incidentally, if you're interested in GTA5 on PC, Digital Foundry put together a feature assessing the various hardware options and what works best with the game.