If you lived in a small neighborhood (or some apartment buildings, if the walls aren't too thick) you could start a little ISP. Or you assign all of the devices in your house an IP address, and even break down the ranges (e.g. N to M are for kitchen appliances.)
The legacy Class As really aren't a significant issue either. By the time you subtract out all the effort that the clawback itself would involve (nontrivial reconfiguration of quite a few major corporate and government networks), it would probably be a wash or quite close to it versus just trying to work on IPv6 -- which finally seems to be getting some traction.
At best I've heard a few extra months added at current burn rate estimates. Hardly worth the knock-down, drag-out fight that it would involve.
I suppose that would depend on what ISPs you're buying transit through.
Technically, the smallest block you can announce that won't be filtered is still /24, and many do, including networks that punch holes in their own aggregates, or their upstream ISPs' aggregates for redundancy, etc.
However, with the global BGP table coming in at just shy of 300,000 routes now, there's pressure to filter small prefixes more and more. There's kind of a de facto gentleman's agreement among the sorts of folks that are in NANOG that /22 should be the new de facto "smallest prefix" wherever possible. I really think getting your /24 announced and propagated (if it's truly a provider-independent block from a RIR, e.g. ARIN, and not just a Class C subnet from an ISP network) might be encumbered by hemming and hawing from routing administrators that are constantly keeping the dwindling capacity of existing routers to hold full BGP views - especially multiple full views from multiple peers - in mind. You can definitely do it, but the appeal of a /24 is slightly diminished in light of that.
devise a numeric code so that users navigating across the ip's are receiving an "important" message. the website navigation plays along with this "choose your own adventure" game.
You could always build a 255 site SEO network and interlink them all for SERP purposes. Class C blocks are big for people building link farms in order to take over the top ten results for different search terms.