It's not pretty but it's certainly clever: tired of trying to play Virtual On on the Xbox 360's standard controller, one nifty modder crafted his own dual-joystick interface out of candy packaging. Of course, there's more to the controls than just upright 'sticks, so a spot of wiring moved the control buttons too.
A few simple push-to-close buttons were screwed into place on the candy sticks, then basic wires fixed to the contact points for the four main buttons inside the original controller. If you had some more time (or inclination) you could certainly tidy it all up with internal cable routing and a more stable base.
Of course, what this shows is that there's likely a considerable aftermarket for twin-stick controllers for the Xbox 360. Until one of the peripheral manufacturers steps in, the DIY projects will have to do.