Famous console modder Kotomi prepped this project earlier this year, yet somehow it slipped right by us. In that case, let us redress that grave injustice right now. What you see here is quite possibly the world's smallest Sega Genesis (the Nomad notwithstanding), functional or not. Kotomi fashioned the mini Genesis out of one of those 6-in-1 TV game devices seen on late-night TV, adding a cartridge slot right on top. Whether or not the cartridge slot actually works is unclear, since Kotomi never explicitly says so in his post. Still, it does look mighty nice.
Megadrive Mini [le blog de kotomi (oldies inside) (in French) via TechEBlog