The right billionaire / fringe group / clandestine evil organization could do something interesting with Bir Tiwal, the largest expanse of unclaimed land in the world.[0]
Bir Tawil and the Danube pockets are claimed, it's just that the border disputes mean that both parties argue it's the other side's claim; should the border dispute get resolved, there will be a clear owner of the land.
Also, if anything valuable is discovered or built there, Egypt and Sudan can settle their claims. Most likely is Egypt taking Halaib and Sudan have Bir Tawil, but could go the other way. Or Egypt could take both by force.