As the title says, what would the world look like today had there not been any great wars during the 20th century? How to avoid them doesn't really matter, there would obviously need to be one or two short wars between France & Germany to finally set things even, probably a Civil War in Russia and Austria-Hungary (maybe the Ottoman Empire as well) would happen but these stay for the most part contained in their countries, and a Pacific war is likely but with a less imperialistic Japan it could be smaller.
I am more interested not on how but on the effects of the world never experiencing an industrialized war on the scale of WWI and WWII. Some technologies might not be around, and others not be as popular.
Cars spring to mind as something that would have taken much longer for everyone to start using.