Sometimes I am wowed about people making full sized consoles smaller. This time I am wowed about someone making an already portable game machine massively cooler. Using a GBA SP one clever modder made a Space Invaders cabinet suitable for mice. The cabinet is 7″ tall, 3.5″ wide and 4.5″ deep and 100 awesome.
To answer Technabob's question, yes this does classify as a portable handheld