Tiny Solenoids

I am interested in making a tactile display based on an array of solenoids controlled by the Arduino using loads of shift registers. Does anyone know where to get cheap and really tiny solenoids? Or maybe how I can make them such that they work at somewhere around 5 volts or 3.3 volts? Thanks :)

There are electronic braille readouts. Typically one line of characters (6 dots), I think.