For the internet? Certainly. Linking electronic computers together via some sort of standardized network protocol is the obvious and natural next step for any physically decentralized entity with many such machines. And as we all know, once you have the standardized network protocol, the network grows and spreads organically. The idea of connecting computers so that they can communicate with each other is not a particularly novel one, and to make the logical leap from the fact that DARPA was the first one to do so to the belief that no one else would have had DARPA not done so takes a rather large set of blinders and a staunch willingness to wear them at all costs.

As for GPS, why not? As electronics shrank and the cost to send satellites plummeted, surely someone would have come up with the idea to combine radio and triangulation to determine position. Though the concept is more novel than linking computers together, it isn't so complex or costly that a reasonable person can say with any degree of certainty that it would never have been done. But my point isn't that the government should invent nothing, it is that the government, despite all of its spending, actually invents very little relative to the private sector.