Common goods, (not public) are so because they are non-excludable and rival. Often this reflects the impracticality of excluding some users, rather than an absolute impossibility. For example, a park is public because it's impractical to be charging everybody that derives a benefit from using it. However, if it becomes easy to track who uses the park, for how long, who looks at the parks, etc. then the park could be financed privately!
Gadgets that track people's use of different goods could change which ones we deem to be excludable and which ones non-excludable....
A basic example is toll roads. If we mount GPS's on all cars and figure out how much tim they spend on the road, we could charge people for their use of streets directly. No more publicly financed road construction!