Are there any tires made that are true 'run-flats?"
I was thinking something like if the tube blew out or leaked up an such if there is some tire that you can still ride slowly but not eating on the rim that has some buffer space so you can keep on rolling around town like a 'run flat' tire? Do they make such stuff? I heard that Humvee's have true 'run-flat' tires.
As to motor vehicle applications, commercial run flat tires have a host of issues that make them a compromise--at best--in many circumstances. To apply that technology to bike tires would be a miserable experience. The ones used in HMMWV's by the military actually have a two piece aluminum donut inside the tire that they can drive on to get out the line of fire and change it.
Car run-flats are designed to "limp home", or at least get you to a gas station. They manage by having much stiffer sidewalls, unlike the solid forklift tires mentioned earlier. With the need for lightweight, and a priority on comfort and speed that are both related to the ability of the sidewall of a bike tire to flex (AFAIK) it would be difficult to make a run-flat bike that used air pressure that anyone would want to ride on or buy... too heavy and too slow, or at least too uncomfortable to be appealing.