Game Courier supports many different games. Here is one picked at random:
Grand Shogi - Normal Shogi but with extra pieces - "Smooth and fantastic fun, awesome action"

Knightrider Bouncy Chess

If you had a Java-capable browser, you could play Knightrider Bouncy Chess here.
Keys "s"=save "l"=load "b"=back once

Stuart Conquest, 1983. This variant has a group of devoted players. Diagonal runners bounce off the walls and knights can move in the same direction as far as their run is unobstructed, and bounce on edge squares.

In this original variant, knights may capture each other. In Knightrider Bouncy Chess II, this is not allowed, and knights tend to last longer.

Chess Variants