There's also the Apple ///'s approach to almost-transparent banking on a 6502. The hardware could redirect the zero page to (almost) anywhere in the 64K address space (foreshadowing the 65C816's movable zero page), and it maintained a sort of second zero page called the "X" page at a fixed offset from the zero page. Then on any indirect access to memory through the zero page, it would check the corresponding byte in the "X" page and if it was valid it would use it as additional address bits. As implemented in the ///, programs could thus directly access up to 512KB without doing any traditional banking or paging.

Of course, it was also possible to do traditional banking on the /// so that program code could reside anywhere in the 512K, but I thought the X page thing was pretty neat when I finally figured it out.