You know how we've all seen Mario with a Portal gun before? Well, somebody is actually trying to make that into a game we can not only watch, but play! It's called Mari0 and is currently in development for OSX, Windows and Linux at two-man team Stab Yourself.
Mari0 will sport not only the original Super Mario Bros. levels, but also all of the Lost levels -- plus in-game downloadable map packs, a level editor and simultaneous multiplayer for co-operative portal slinging. Seriously, read that sentence again and then click this link.
Like many (if not all!) of you are, we're behind this project entirely. Let's just hope we can all snag it before Nintendo's lawyers shut it down.